I just realized ....
There's two ways to fly turbines w/o needing to go through AMA:
Option 1: Join Flite Test Community Association. No restrictions at all on power source. All you gotta do is stay below 400 AGL. It's certainly possible to do that with turbines helicopters quite easily. It's more challenging with FW, but I know I've seen video of 80lb turbine FW operating at Apollo Field in Los Angeles where the limit is 400 AG (or less).
Option 2: Get your 107. If flying helicopters, probably no need for anything more. If flying fixed wing, will likely need to ask for speed waiver.