See the
end of the Font, Screensaver, and USBNetwork thread.
Leading up to here:
https://www.mobileread.com/forums/sho....php?p=3135677
Basically, you're right. And the prognosis is not good -- unless perhaps you can somehow update YifanLu's frankenstein hack.
As for which hack -- according to YifanLu you use the same hacks as the device's original firmware:
https://www.mobileread.com/forums/sho...19&postcount=9