And just for good measure:
The "Sysctl Enabled" one is working fine with Rjlov's voladj, Rjlov's IOctl with the startup chooser, and the radio works both in the car and in the house. And it doesn't induce the garbage screen bug (after several retries) So I'm gonna use that one for a while.

Although I just induced what I think to be another bug unrelated to all of this: If you soft-reboot the player when it's on FM tuner after a flash upgrade, it'll restart in sleep mode (display off, standby light pulsing), but the tuner is active and sending audio out the home outputs.
___________
Tony Fabris