Though after sorting out the stupid kernel panic (from Google's weird shenanigans), I have successfully booted Android 12 on Unihertz Atom L and it seems to be working just fine.
The kernel panic I ran into was due to a stack of dm-verity over loopback over dm over ext4 fs w/ inline crypt over ufs storage driver. The panic was due to a bug in issuing direct I/O from the loopback device over the encrypted and mapped underlying fs. Somehow it caused some sort of alignment issue and made the kernel bail out.
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