Why shouldnt you be able to modify, all you need is that socket interface thing. For all purposes you should be able to ducktape the R unit and just buy the R unit socket interface unit for any kind of the ship :D.
Edited By: Ethan Travis on Year 17 Day 143 3:21 ____________
''If gods do exist, we need to start looking for ways to kill them''
Id argue that it isn't that simple since Astromechs perform physical hardware repairs as well as software, therefore the position of the astromech can't just be anywhere. The design of the ship will be built around the astromech so that critical areas for repair can easily be reached from its mount. Engineers who designed ships without the requirement of an Astromech never had to worry about that during the initial design phase.
It would be a lot more complex than just retrofitting a plug.