I rooted mine back in 2014 and found it useful and quite stable. I haven't investigated the scene since so it may have progressed significantly.

You can configure it such that the Nook would boot and appear as normal, but holding down a key took you to the android launcher, and you would give up the use of two (redundant) buttons of your choice to control android-specific actions like <back>, etc.

This system was limited -- at the time -- to an older version of Android with limited app support, but if your purpose is to create your own apps this shouldn't pose any problem.