Sounds like some bad information is being passed around. Grip mods are legal,spacer plates aren't for weight, they are for safety and size adjustments. I shoot pachmayers because they have plates molded into them. I had a 38 super blow out and those grips saved my hands.
The 10 mm "production" gun doesn't have to be a factory gun. You can make your own as long as it is a Production spec gun. No long dust covers and the rest of the forbidden mod list.
No gun is allowed a tungsten guide rod. Only steel is permitted.
Lets face it there are always ways to "game" anything. Rob could kick my butt with a Daisy and a "gamers" gun wouldn't help me.
I've seen guys with huge magwells that wouldn't fit in the box, carrying 7 and 8 round mags in case the senerio lends itself to the gamers edge,The one I like is the "French" cuts on the slide and milling to lighten it.
What I would like to see is IDPA major matches include in their fee the amount of factory cartridges you will need to shoot the match. All the 45 shooters would shoot the same 230 ball, as well as the 9mm's, and so forth.When you register you just tell them what you will be shooting and they will tell you what you're getting. Then you can go get a few boxes of the stuff and set your gun up to work with it. Hows that sound, everyone shoots the same power factor in their division and we are left with judging skills and speed.
I've yet to have my gun checked at any IDPA event,even the nationals. I guess I have too much self esteem to cheat, but I can see the opportunity for others if they were so inclined.