A game changer for sure, congratulations @tony on the birth of a new Twiddler, the T4k. As I understand it, each row of buttons now has 8 states (0, L, M, R, LM, MR, LMR, LR), 8x8x8x8 = 4,096, or 4k. Even without the awkward LR there are 2,400 chords, nearly ten for each T256 chord. This staggering increase is somewhat daunting for us old T256 hackers. I'm with @AlexBravo on this one, not sure I have it in me for the necessary total rewrite.
Also echoing @AlexBravo, the first step is to get some data on the speeds of the new chords. I developed Twidlit for just this purpose with T256, but it needs to load the Twiddler's configuration. There must be a new extended cfg file format, what's the time-line on that being made public @tony?
I should mention that Twidlit's random chording method of determining chord speed takes the average of 16 instances of each chord by default. As I recall, this takes less than 2 hours (no necessarily in one go) with T256. Now we're looking at something like 20 hours! Perhaps we need more pruning than just taking out LR.