Yeah, the issue was that WS2811 and the servo pin 3 shared some resources, and it didn't gel. dRonin has two ways to do DShot. The first one is to bitbang the stuff out directly to the pins via GPIO, that works pretty well, except that it disables interrupts for the amount of time it takes to send the signal. That doesn't work well with timing sensitive stuff, like the OSD on Seppuku, that's why there's also a DMA-based implementation. I switched the Revo over to it, because why the hell not. Seems like I didn't test it with WS2811, or at least not sufficiently well, because the PD2 pin, which seems the most obvious option, doesn't cause any issues. Any next builds from now on use the GPIO version and should be fixed.
There was a way to make the DMA version work (well, not lock up the system), but it'd require an awful lot of trust in ESC firmware to do proper data checks, and knowing BLHeli, that's a lot to ask for. Unless you like your ESCs to disarm or go full throttle for a millisecond at random. Considering some bugs in other code of mine causing equivalent effects, that didn't really sound nice on the motors. :V