I wanted to post a follow-up here for others who might come along later.
The modifications described here:
https://twll.blogspot.com/p/nook-fir...rovements.html
are said to be specific for FW 1.5. The developer cautions against trying them with other firmwares.
I am very pleased to report that it all works just fine with FW 1.7 (probably 1.6 as well). The initial reboot after replacing android.policy.jar is scary slow, but eventually the device starts up and you've got a lot of new and useful features!
Requires root, of course.