Just rubber o-rings on regular switches (instead of low-profile switches) might be enough to reduce travel length, and as a bonus to make bottoming out soft and silent, like on rubber dome keyboards. At least on MX, not sure about dampening rings on Matias.

Also, to add "chickletness", there are XDA and G20 keycap profiles, which are, AFAIK, especially popular to put on "ergonomic" splitted boards.