I've built/rebuilt seventeen engines since October for various friends. All OS 91's. I can tell you with certainty that SPA is not going to fiddle around with the glow engine rules. It has nothing to do with the cost of flying. What we can do with an engine is not fully regulated, and yep - some of us are going to fiddle with them. A lot of people wish they knew how to fiddle with 'em, and some even claim to know how to fiddle with them.
Got to go warm up my blueprinting machine and get my prop polished and drink some port!