[=;536320]
Well that was actually the first thing I tried, however with my experimentation the first person character seems to react poorly to having physics simulated on it or its components, resulting in odd behavior with the inherently non-physics based movement that the character uses – the player was unable to move.
[/]
There is this Unity game Worlds Adrift which is running a mix between animated character and physics swinging. It still looks a bit dodgy when the character is swinging because it seems to be only one constraint that is used and the rope could as well be a long stick, but at least they got the mix to work. The animations also need some work.
But as you say, for true swinging you need to run all physics based.
Like the angular momentum that kicks in when the ropes are fully stretched at the balloon at 1:50min in the R.C. Bot Inc. gameplay footage above, such a realistic swinging is really only possible all physics based.
https://.com/watch?v=LM2QZXXy8Rc