Thanks for your follow-ups, uboot and tartanpion!
I've added the CoolReader configuration to the dot.pgdn file and will release an updated .zip soon. (It's already on Github.)
The Autostart author has sent me (an updated version of) his app's source code and has given me permission to modify and redistribute it. With it, I may be able to build an all-in-one APK that installs and runs the pgdn daemon automatically.