Yeah, Unfortunately this seems to be the case...
The following has been copied directly from the AMA Form# 510-A (SAFETY REGULATIONS FOR MODEL AIRCRAFT POWERED BY GAS TURBINES) Paragraph 13...
13. Afterburners are prohibited. Other special controls such as water injection, thrust reversers,
variable nozzles, etc. are acceptable only if engine manufacturer provided and supported by
development testing and user training.
Bummer [>:]
George