Fair enough. That wouldn't be my cup of tea, personally. Apart from anything else, the roads in AC where you might want to cruise around with friends will surely have have corners now and then that aren't compatible with cruise control, no? IRL, I use cruise control on motorways/highways, not on country roads
I reckon there won't ever be a straightforward AC app to do this, because I'm pretty certain the AC app API doesn't permit any kind of control of the pedals. You'd probably need an AC app to feed car speed data to something like a virtual game controller which could combine the physical pedal and the cruise control inputs.
Honestly, while it might be a fun project to work on, I suspect the number of users of such a thing
in a racing sim is probably in the "fingers of one hand" zone for the entire planet