It's actually not harder than with any other engine out there. There are certain design approaches that GO has made and formed a very competitive engine lineup. In most cases guys just don't listen what they are being told to nor disregard the info and then blame on the gear if it fails.

Be it the GEN 5/5.5 or the new GX series engines, just do the basic steps:

Install run-in shimm
Put in hot plug (like OS P3)
HEAT the engine to +100degC meaning BOTH the heatsink and block is in +100degC
Loosen the plug
Prime the engine
Start it
Fasten plug
If engine tends to stall screw in LSN 1/4 turn and that should do the trick

It's not difficult and in most cases people dont really heat engine enough (use hair dryers or something crap), don't have starter box batteries fully charged or the car is not aligned correctly so the wheel touches chassis or something stupid like that.

When speaking of the con.rod stress. I think atleast 9/10 reason for rod giving up is that the user has not made sure the engine stays in +100degC when running in. If done properly you don't have problems with rods and for all racers it should be normal to change the rod anyway when the engine has bedded in. It's not a cost issue as you already have saved a lot by not buying a "high end mill" for nothing and considering the Go spare prices it's really not a issue to anyone. People are just so lazy and it's easier to blame on the engine than yourself not maintaining it.