[Sony Xperia XZ Premium ROMs, Kernels, Recoveries, ] saved-j:
First of all, you WILL need an Unlocked Bootloader. I hope you know what it means, otherwise you'll have to RTFM.

#. Long ago I've learned from some wise guy who recommended to always flash a full stock FW before installing a custom ROM based on it. You MIGHT or MIGHT NOT want to do it. But I've NOT tested this FW without flashing the full .270 image upfront via Flashtool, with FULL wipes. (Or, flash 16.20 if you want to go for the 1.8.0. Also, HERE is the discussion on it)

Or this .235:Newflasher+.235

0. Push the Aroma-ready TWRP via ADB.

1. Boot into the Recovery (hold power&vol-) and install the ROM. You DON'T HAVE to reboot afterwards, so you might want to add all the other ZIPs to the queue.

2. Install the Xposed-v90-SDK26-arm64-beta3.zip, which contains - no surpsise - Xposed SDK. You might want to install the SYSTEMLESS version of it, but you will need to find and download it yourself and install it at THIS step, instead of this particular zip.

3. Install the Xposed FIX. It has to be done separately for an unknown reason. I've decided NOT to play with it, trying to embed it into the ROM itself, and left it as a separate zip. MAYBE you don't need it if you're not going to use Xposed, but why use this ROM at all then??

4. Install the Kernel Patch. It's the standard Kernel Patch from JanJan.

5. Optionally, you MIGHT want to install the Sound Mod. I recommend you NOT doing so, because the volume on it is cranked up TOO much, and on my device it began producing crackling sound not even reaching the maximum volume.

6. HERE I INSTALL GAPPS. You might NOT need to do so, but if you want to use the phone with Daydream VR, and also if you might want to use Google Camera (sadly no HDR+, but I use it mainly for a cool Bokeh and 3d panoramas!), you'll need to install the SUPER arm64 8.0 package, which is almost 1gb big. Don't worry, we're going to debloat our device in step 7, deleting 80% of that crap...

p.s. To enable Daydream, install Daydream Enabler magisk module from repo

p.p.s. To enable Google Lens, install Google Lens Enabler magisk module from repo. It will also let you backup the photos with the Google Photos app in original quality as if it were the Google Pixel FOR FREE! It WON'T TAKE UP YOUR SPACE!!!

7. Debloater. Here is what it removes:

delete_recursive("/system/app/AdvancedLogging");
delete_recursive("/system/app/AnonymousData");
delete_recursive("/system/app/Books");
delete_recursive("/system/app/com.sonymobile.infoapp");
delete_recursive("/system/app/com.amazon.mShop.android.shopping");
delete_recursive("/system/app/com.facebook.appmanager");
delete_recursive("/system/app/com.facebook.katana");
delete_recursive("/system/app/com.s.antivirus");
delete_recursive("/system/app/com.sonyericsson.xhs");
delete_recursive("/system/app/com.sonymobile.xperialounge.services");
delete_recursive("/system/app/com.spotify.music");
delete_recursive("/system/app/com.swiftkey.swiftkeyconfigurator");
delete_recursive("/system/app/com.touchtype.swiftkey");
delete_recursive("/system/app/DemoAppChecker");
delete_recursive("/system/app/DeskClock");
delete_recursive("/system/app/DMAgent");
delete_recursive("/system/app/Exchange-release");
delete_recursive("/system/app/ExternalKeyboardJP");
delete_recursive("/system/app/externalkeyboardsinternational-release");
delete_recursive("/system/app/FitnessPrebuilt");
delete_recursive("/system/app/fota-service");
delete_recursive("/system/app/Gmail2");
delete_recursive("/system/app/GoogleHindiIME");
delete_recursive("/system/app/GoogleHome");
delete_recursive("/system/app/GoogleJapaneseInput");
delete_recursive("/system/app/GooglePinyinIME");
delete_recursive("/system/app/GoogleZhuyinIME");
delete_recursive("/system/app/IddAgent");
delete_recursive("/system/app/KoreanIME");
delete_recursive("/system/app/Newsstand");
delete_recursive("/system/app/Lifelog-googlePlayLiveRelease-4.0.A.0.14-8388622");
delete_recursive("/system/app/Music2");
delete_recursive("/system/app/newssuite");
delete_recursive("/system/app/PlayGames");
delete_recursive("/system/app/playstationapp");
delete_recursive("/system/app/PlusOne");
delete_recursive("/system/app/PrebuiltBugle");
delete_recursive("/system/app/PrebuiltDeskClockGoogle");
delete_recursive("/system/app/PrebuiltExchange3Google");
delete_recursive("/system/app/PrebuiltGmail");
delete_recursive("/system/app/PrebuiltNewsWeather");
delete_recursive("/system/app/SemcEmail-release");
delete_recursive("/system/app/SemcWarrantyTime");
delete_recursive("/system/app/SomcMovieCreatorRmm-release");
delete_recursive("/system/app/Tycho");
delete_recursive("/system/app/Videos");
delete_recursive("/system/priv-app/com.facebook.services");
delete_recursive("/system/priv-app/com.facebook.system");
delete_recursive("/system/priv-app/com.sonymobile.retaildemo");
delete_recursive("/system/priv-app/EnterpriseService");
delete_recursive("/system/priv-app/NexusLauncherPrebuilt");
delete_recursive("/system/priv-app/sonyentrance2-release");
delete_recursive("/system/priv-app/textinput-chn-xxhdpi-release");
delete_recursive("/system/priv-app/Turbo");
delete_recursive("/system/priv-app/UpdateCenter-release");
delete_recursive("/system/priv-app/usb-mtp-backup-transport");
delete_recursive("/system/priv-app/usb-mtp-factoryreset-wrapper");
delete_recursive("/system/priv-app/usb-mtp-fotaupdate-wrapper");
delete_recursive("/system/priv-app/usb-mtp-update-wrapper");

Voila.