So firstly, why does "Remove" even appear if you can't use it? Is there some circumstance in which it would not be greyed out?
Next, if this really is not an included feature of Studio One, can it be? Studio one can in fact remove the Aftertouch data - IOW the function itself exists - but I have to laboriously scroll through the whole song to select all of it. Why not simply enable that greyed-out "Remove" to make it easier?