Something that should be fairly simple to implement, but extremely useful would be to add a kick feature.
I use my Helix LT live all the time as a troubadour, and I bring my SPD-ONE kick pedal with me. It costs almost 300 euros, weighs a lot, I use ONE kick sound from it and have to play the whole song through unless I loop it. And you know how hard the looper feature is to get perfect rhythm wise.
Therefore, a feature where a simple kick sample would play 4th notes set from the tap tempo would be amazing.