Great post, it's a pity I hadn't taken on board the difference between shunt & series RRs before I got my replacement. At least I had understood about all the fakes about & got a s/h genuine SH020
I was able to get it in the original position with a bracket I made up, maybe the seat on an S4R is a little different. However the cables take a very tortured route & with all the heat they generate, I might look at repositioning underneath as yours.
Dave