Issue 1:
It should be possible to pull down from the top of the persistent bottom sheet to make it disappear, but it seems to have a very small hitbox to make that happen?

Issue 2:
Trying to figure out why this is occurring but currently no idea. I just came across the issue in the console.

flutter: When the exception was thrown, this was the stack:
flutter: #2 MultiChildRenderObjectElement.forgetChild (package:flutter/src/widgets/framework.dart)
flutter: #3 Element._retakeInactiveElement (package:flutter/src/widgets/framework.dart:2868:14)
flutter: #4 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2895:32)
flutter: #5 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4759:32)
flutter: #6 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
flutter: #7 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
flutter: #8 _TheatreElement.mount (package:flutter/src/widgets/overlay.dart:493:16)
flutter: #9 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
flutter: #10 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
flutter: #11 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #12 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #13 StatefulElement.update (package:flutter/src/widgets/framework.dart:3799:5)
flutter: #14 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #15 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #16 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #17 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #18 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #19 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4661:14)
flutter: #20 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #21 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #22 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #23 StatefulElement.update (package:flutter/src/widgets/framework.dart:3799:5)
flutter: #24 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #25 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4661:14)
flutter: #26 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #27 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4661:14)
flutter: #28 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #29 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #30 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #31 StatefulElement.update (package:flutter/src/widgets/framework.dart:3799:5)
flutter: #32 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #33 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #34 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #35 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #36 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #37 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #38 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #39 StatelessElement.update (package:flutter/src/widgets/framework.dart:3702:5)
flutter: #40 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #41 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #42 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #43 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #44 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #45 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #46 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #47 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #48 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #49 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4661:14)
flutter: #50 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #51 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #52 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #53 StatefulElement.update (package:flutter/src/widgets/framework.dart:3799:5)
flutter: #54 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #55 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #56 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #57 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #58 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #59 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #60 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #61 StatefulElement.update (package:flutter/src/widgets/framework.dart:3799:5)
flutter: #62 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #63 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #64 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #65 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #66 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #67 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #68 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #69 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #70 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #71 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #72 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #73 StatelessElement.update (package:flutter/src/widgets/framework.dart:3702:5)
flutter: #74 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #75 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #76 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #77 StatefulElement.update (package:flutter/src/widgets/framework.dart:3799:5)
flutter: #78 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #79 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #80 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #81 ProxyElement.update (package:flutter/src/widgets/framework.dart:3909:5)
flutter: #82 Element.updateChild (package:flutter/src/widgets/framework.dart:2699:15)
flutter: #83 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
flutter: #84 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
flutter: #85 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2242:33)
flutter: #86 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:626:20)
flutter: #87 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
flutter: #88 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
flutter: #89 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
flutter: #90 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:751:7)
flutter: #92 _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
flutter: #93 _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
flutter: #94 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12)
flutter: (elided 3 frames from class _AssertionError and package dart:async)
flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════
flutter: Another exception was thrown: Duplicate GlobalKey detected in widget tree.
Reloaded 2 of 423 libraries in 394ms.