The default Kinesis firmware is fairly limited. It has what they call tap&hold, but it is too limited to be useful in practice. So, it’s mostly limited to simple remaps and macros. That does have the advantage that you don’t fall in the customization rabbit hole.

That said, I made a KinT controller for my advantage, so that I can run QMK.

I played around with different tap&hold durations (how long you have to hold before it registers as a hold rather than a tap), but I just couldn't find a duration that matched my rhythm. I kept getting holds when I wanted taps (for short durations) or vice versa for longer durations. My current config uses tap&hold on two keys (home and end, which I don't use often anyway). Holding leads to "hyper" and "meh" which are two extra modifier keys (like control or alt/option/meta). I'm an emacs user so extra modifiers means I can basically store as many macros as I want!