you could "hack" that in manually with the Steam controller settings I bet.
map ALT to touching the touch pad, map the touch pad to mouse input.
if the game has no issue with simultaneously mouse and controller inputs then it should work.
EDIT: tested it on the Deck, and yup, it works pretty well.
what you do is go into the steam controller settings, go to the right trackpad, set the trackpad input to mouse.
set the sensitivity to around 250% so that you can easily reach each corner of a hack without having to lift your thumb off the pad
then map clicking it to R, that resets the hack if you do something wrong.
and map touching the trackpad to ALT, which initiates the hack.
here a short video from the demo showing me using this: