Thanks as always for your detailed answers.
Yeah I'd most likely use PC6 to transmit to an OSD instead of HOTT. So it looks like I'll get to be the guinea pig using it for other purposes. That leaves me with M5, M6, and M8. These will go towards a camera gimbal system... maybe the STorM32. Not sure 3 PWM will be enough. I still have 1 PWM left on the actual M4, but I wanted to use that for a buzzer. I might have to tap the extra PWM lines going to the on-board ESCs. Then I'm thinking of using the TX/RX and 5v lines for 3DR Telemetry. No BT. This should make for a nice FC board combo that should do enough of what the AQ6 does.