Currently experimenting with this on the PW2.
So far, appears not to blow up horribly, so that's that, at least. Getting anything to show up in the Aa menu is possibly doable, but potentially way more trouble than I'm willing to go through.
On the good news front, font overrides work, and since Caecilia Condensed is useless with a custom FreeType, that's the perfect target for such a thing.
I'll update the snapshots
in a while, but the doc updates will have to wait, so the strong warning still applies, and I'll urge anyone even remotely looking to try this to *thoroughly* read the first post, be fairly proficient in Kindle twiddling, absolutely have an SSH shell open at all times during setup, be very wary of reboots, and, as a bonus, be familiar with the specifics of this Hack on a safer device (ideally, a Touch, barring that, a PW1).
TL;DR:
Here be dragons.
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As I said, I'm not terribly inclined in digging further into the whole Aa menu thing (and I'm a bit short on time, which doesn't help), so if anyone has any insights into that, I'm all ears
.