[Magisk] TacoShow:
*sigh* (of relief)

So a little while back I stated that I had problems here that I couldn't get Magisk to root my phone, and I've finally 'fixed' the issue. 'Fixed', because I only avoided the problem, and still haven't found the root cause. I'll explain:

I backed up all my sh*t as much as I possible could (backing-up, which required to be more than just a TWRP backup, being ironically a pain when you're not rooted).

Factory reset my phone to ROM's stock state.

Reformatted my SD card, but keeping it as emulated storage.

Flashed the latest Magisk zip (from a USB stick) via the latest TWRP, which resulted in error 1 during flashing.

Removed Magisk by flashing the latest Magisk Uninstaller zip with TWRP.

Flashed a boot.img file (don't recall where I got it from, as this rooting project of a hot potato had been stalled for a while), again attempt to flash the same Magisk zip, which worked.

Rebooted, and installed the latest Magisk Manager, as well as Root Checker.

Launched Magisk Manager, and it said initially offered me to download the latest Magisk zip as Magisk wasn't installed. Declined, reloaded the page, and MM said that Magisk is installed, but required to download a setup zip to complete the setup.

Setup zip downloaded and attempted to be flashed; setup failed.

Checked Root Check: device unrooted, Satefy Net check passed (obviously).

Then I formatted the SD card to portable storage, and factory reset phone to ROM's stock state again (using LOS 16; see my original reply I linked to earlier in this reply).

Booted back into TWRP, flashed the same boot.img again, flashed the same Magisk zip again, boot back into system, installed MM and Root Check again: device rooted, both confirmed by MM and Root Check, as well both confirming passing Safety Net.

Formatted SD card to internal/emulated/phone storage again, and still Magiskly rooted, still passing Safety Net.

So the conclusion is that, for some reason, Magisk just won't root when using emulated storage. I had a strong suspicion that this was the case, as on my other phone, that is practically the same as this one (my current phone is the Motorola Moto G Titan, and the other phone is Motorola Moto G Falcon), which didn't have emulated storage (not possible because: no SD card slot), and rooting the phone worked at the first attempt, despite both having the latest TWRP, Magisk zip, Magisk Manager, and LOS 16.

That said, I'm not satisfied, because I still haven't found the root cause on why Magisk doesn't work with emulated storage.

So now I'll try to flash my TWRP backup that I made before all this, remove the SD card from storage pool after restoring, but without resetting LOS 16 to stock this time, and try to root again, so that I can be 100% sure that it is because of emulated storage, and not something else in my setup pre-reset that held Magisk back.

Edit: also when I'm done with my current phone and upgrade to a current gen one in the future, I'll likely never face this problem again, as internal phone storage is much larger than a mere 8GB, large enough to hold all and any app that I want installed. But that I discovered this was a fun experience and all in the name of broadening my knowledge... I guess.