Running a wire for high current traces is kind of risky I think.
It's not that I would not do it if I had to revive something and did not have any other choice.
However for some applications I would rather cut out an entire new trace and attach it to the board and exchange the rivets connecting top and bottom layer (I have a Bungard press for this).
Which is why I was asking for the self adhesive copper foil.
It seems to me that 3m conductive copper foil would be an option, however a friend of mine will send me some to repair my preamp.
Procedure is:
remove Solder mask, cut to fit, put on, tin it, check continuity, reapply solder mask
obviously the pcb needs to be inspected for cracks and damaged traces, and that is where the microscope comes in.