[Lenovo Zuk Z2 Pro ROMs, Kernels, Recoveries, & Oth] Terminator.J:
I'm not trying to attack you by the way, and I still want to help make sure you've got a working QPST/QFIL setup on your computer because I do believe it'll help make sure you have the best experience going forward. But I'm also appreciating the discussion, and I hope some other folks will chime in (and we can take it elsewhere in the forums if needed - I know it's getting a little off-topic).

You've installed custom roms. Without QFIL in-between. That touches more than just /system, /data, /boot, /dalvik-cache, or /cache. It touches /persist where your device sensor configs live, it means you're modifying NVRAM areas like /modem-st1 and /modem-st2, and now, with the Treble-compatible TWRP fstab mounting /factory as /vendor, you're modifying /factory. There's probably many more. But you're not resetting them to a known-good factory state in-between, which is the entire point of this discussion.

What everyone recommends. Go look at troubleshooting and how-to guides throughout the Z2 Pro forums here and on zukfans.eu. It's all about starting with a QFIL flash which will reset your device's partitions to a known factory state before custom ROM installation. How much time have you spent looking at the files included in a QPST package, or digging into the XML to see what they're flashing? They've got a full GPT blank partition map included; it wipes out and re-loads whatever Lenovo thinks needs to get wiped out to factory flash a phone.

It's been reported that you might be able to flash just a persist.img that corresponds to your last-flashed ZUI version to recover from non-working sensors, but it's safer to just QFIL flash the whole thing. And I literally just flashed 1.9 before 3.1 three nights ago, and re-unlocked my bootloader. So I *DO* do that.

Like I have already said, what I disagree with is the generally proposed troubleshooting/clean flashing advice of starting with 1.9 and then doing OTA updates... more steps = more points of potential failure, especially when you're transferring over the internet from servers in China. I feel like it's superstition that we're passing along because it usually works; it's true that it's a slightly more complete troubleshooting option because it also restores a locked bootloader, which all later factory QPST packages don't touch. But if I have no reason to believe that my bootloader is messed up, as I have no problem getting into & out of it or using fastboot commands, then it's also a big waste of time. My advice continues to be that if you're trying to do super-super clean or need to troubleshoot, you should QFIL flash 1.9 then QFIL flash 3.1, rather than only flashing 1.9 then downloading OTA updates and risk those being corrupted in-transit or wasting the time/download bandwidth to get and apply several updates over & over again. As far as I can tell looking at the QPST installation packages, it's just as thorough (other than bootloader), with fewer opportunities for something to go wrong.

I didn't start from 3.1, I just understand that since it's literally blowing a new GPT partition map over the storage and filling them with the appropriate images, it's not a mixed state and it is a clean state. But since it had been a while since I last touched my bootloader, I decided to start with 1.9 before going to 3.1 before going to 3.5.316 OTA before unlocking bootloader & going to custom ROM + 3.5.344 baseband via TWRP-flashable zip.

Good, I'm glad it's working better now, but that shouldn't make you think you're right about avoiding QPST/QFIL. The BLoD could be from the bluetooth radio freaking out, could be from someone using a poorly-configured thermal-engine.conf that has an artificially low temp limit and it thinks it's overheating, could be from using a custom kernel with aggressively low voltages for given clock steppings, could be from failure to change clock states trying to come out of deep sleep at a certain time (like alarm going off, ugh, that one's awful). It's the Z2's general "I think I have a hardware failure and I'm going to hard crash to avoid potential physical damage by trying to continue", and I'm glad you're not getting it now with the latest radio firmwares.

Again, not trying to pick on you, but I think you're doing yourself a disservice AND wasting peoples' troubleshooting efforts if you're not willing to start with a QPST/QFIL flash, and I'm hoping I'm giving a good explanation as to why.