[Google Pixel 4 XL ROMs, Kernels, Recoveries, & Oth] GROOVYJOSHCLARK:
I am so sorry, somehow I missed / overlooked what you meant when you said the percentage, that threw me off. I misunderstood the percentage for the ROOT / ADB push, but not the ROM install itself, I have had this myself before. Easy peasy workaround. You're saying you can't get 10 to even install, it's error'ing on the adb sideload I take it?

We can get around that with TWRP. Now that we have a working TWRP for 10, we can use TWRP to install but you'll need to get back to 10 firmware (the one I laid out above), and when you do get back to 10, quickly go through the OS setup (stock firmware - 10), then once done, install a kernel that works with TWRP and 10. Once you have a working TWRP with kernel, then ADB boot TWRP, factory reset and copy the ROM zip to SD, then simply use TWRP to install the ROM from internal SD (no ADB sideload needed). This removes the ADB sideload hiccup failure.

I'm not on the 11 version right now, so I can't advise on those other issues you reported with 11, but using TWRP will work to get you on 10. Since you will do the install from TWRP and not ADB, you will get past that issue. Then setup 10 PD OS, and install magisk then patch the boot.img (from the 10 ROM using python to pull the boot.img to patch in MAGISK) and you will have a rock solid 10 PD with root and pass safetynet (I had to also install the universal safetynet module).

Once you get 10 working and setup the way you like it, betcha you don't leave PD 10. I didn't, it's so stable, I almost never reboot, and forget about plugging in, if I let my phone idle (not playing games and only use it for email, txt, and calls), it lasts 2/3 days. I only plugin when I'm playing games or it's been a couple days. I took a screenshot of my battery, it was last plugged in 14 hours ago, 72 percent left and I streamed showtime anytime all night long, overnight to my TV (and obviously not plugged in or on wireless). I still have this much battery leftover after a night long stream (plugged in 14 hours ago), it's amazing to say the least! One thing I will add in is that I do disable all apps autostart for games and apps I don't want running in the background using SD Maid (but any root app manager to can do this). I get incredible battery life with 10 PD and stopping those apps from running on their own. With my job and kids, I cannot really ever go without using my phone so I truly do not know how long it will last sitting at idle. My best guess is it would be days based on what's left after using it for calls, texts, and emails after 36 hours of what I've seen so far. 36 hours was as long as I could go without going on the road (IE having to plugin for the road trip) so I cant comment past 36 hours idle and once on road, that uses more battery with roaming but still, 36 hours is great I'm my book! And NO, I am not lying or exaggerating, 36 hours was at idle, using only calls/txt, and yes it truly lasted 36 hours, then I plugged in, and left but I was low, I was at like 2 or 3% left after 36 hours, but still, 36 hours idle, no phone has ever gotten this much idle time for me, so this was cool to see it last that long!