Boobala, The knurling I heard of back in the day was to restore the ID of guide, not the OD for reinsertion. Is that what you mean? BTW the consensus then was that knurling the ID was really not so effective . That process displaced part of the worn ID and forced it to raise, followed by the final reamer pass. If I remember it was often used on guides cut in the base block. I think it was considered a short term fix? I did have a little English 1600 with guides that were metal o-ringed. Can't remember which side, though.
Top level auto repair shops routinely run "scratch tests" or other tests for softness of overheated, liquid cooled, aluminum heads before attempting to repair them. So the notoriously hot-running air cooled engines seem even more prone , whatever the cylinder arrangement.
The big Harley parade bikers go to great lengths to keep the rear cylinder below 300F when moving at lawn tractor speeds.