I have never had PCM mask a problem with a servo. I do not understand what type problem you mean. IF a servo is going to fail it will fail. I have worn many out to failure. I have never had a servo cause a problem with a receiver either so I might be missing something in that area..
Well my transmitter that failed was a 1980's series and it failed in the second year, it was ranged checked also but that didn't help the hard over on three servos when you turned the unit on next to the transmitter. Went back twice to futaba, then hit the Garbage (it was top of the line to). Some systems just don't work..That model didn't as futaba stopped making it after a couple years.

Thats what works for me so I stick with it, everybody has a different method I guess.

V-Snap