Just read an article that contains some interesting AS3 performance conclusions that seem like they'd make good FlexPMD rules:
“If you want speed you should not be using plain functions, local functions, or Function variables. This should give some hint as to the speed of Flash’s package-level functions like getTimer() . Further, you can get big speedups by foregoing static functions, calls trough an interface, and calls throughsuper, especially if you’re going to be using that convenience a lot. The rest of the functions are as fast as you can get. Don’t let anyone tell you that access specifiers matter, calling through this adds needless slowdown, or overriding is handy but slow. It is handy, but it’s not slow.”
Do these recommendations fit the bill for FlexPMD rules? If so - I'd be happy to write it up in JIRA.