Mine finally arrived yesterday.
I put together a few different patches to explore. Here’s some early madness:
Love it. Does what it says on the tin! 
I can see the desire to change the length behavior, for sure. Additionally, I really wish there was a way to return to the originally locked pattern with once Deja Vu wanders away. I like what it does, but I’m after more traditional structures, and returning to a central concept would be nice without requiring an external sequencer to manage that.
Maybe… Store the initially locked pattern. Long press X lock, which then flashes. Sub-12 o’clock values then reintroduce the original values until all are included. Tap X lock to return to standard locking behavior.
I wonder how hard it would be to implement… 