Sooo... playing the PS4 version of the game via remote play doesnt give you vita touch inputs? and why should it, play the vita version you'll get free with crossbuy.
Sooo... one game, *being played by remote play and not as companion screen* doesnt do it so its proof it will never happen?
I guess your point is valid since the 3DS touchscreen works when playing WiiU games remotely.....
.. OH, WAIT!