This is super easy to follow code and such an important utility imo. What is super nice about having this in Max land is that you can do all the testing in memory whereas with the CLI I have to write/read from disk which is slower, albeit not that much given ubiquity of SSDs.
What made you come to the linear interpolation approach? You have inspired me to inject this functionality to the REAScripts but I just went with a brute force method, given an aggressiveness of how far it searches. I then add noise to the exploration amount so that you dont get stuck in a loop of * 2, / 2 ,* 2.
EDIT:
If you want to peek 
https://github.com/jamesb93/REAPER-Scripts/blob/auto-param/flucoma/noveltyslice-auto.lua