I would really really love to be able to at least open and close the valves/angle cocks on the end of each car when coupling at the very least. Ideally i would love to be able to attach the air hoses as a separate action, then also open the air valves to couple the cars. The mechanic of connecting the screw link couplers by hand is already there, so why not be able to increase immersion by making the coupling process more involved? Perhaps this could be something you could turn on and off as you please if you just wanted to do things more simplistically. But I think having this option would really elevate the simulation aspect of it.
To be honest, I'd be happy if all trains would just couple poperly. Neither the TGV or the ICE can uncouple and the TGV cant couple properly.
The TGV and ICE3 trainsets are semi-permanent EMUs; they aren't supposed to uncouple, except as a shop job. The exception to this is the ability to couple two ICE trainsets together to make one double-length train.
I am well aware that both of those trains are Multiple Units, I war referring the Scharfenberg Coupler between the two seperate units. Those are used in normal service at a few locations and do not work as intended in TSW.