Thanks for those answers! Yes sir, using shikigva=80. If I changed to iMacPro1,1 would I simply delete this line from config.plist? Any concurrent changes needed for the AAPL,ig-platform-id entry?
I did spot that TweakTown post with the BIOSes, but being unfamiliar with TT I didn't know what to make of it. I take it you find them reputable/trustworthy! Any other concerns about the f9k beta specifically? Being able to toggle CFG fix in the BIOS is a huge draw obviously.
I think I've gotten confused along the way regarding the right USB header for Bluetooth — I have been plugged into the even numbered header (F_USB2) and that's been working (99%) fine, but in your first post you advised to use F_USB1. When trying that, Bluetooth broke
No sweat, I'm back to F_USB2 now as I quite like using my Magic Mouse & Magic Keyboard.
Any insight on whether the BT card I've used could/should behave differently than yours? Airdrop is not allll the way there yet for me (it's hit or miss), but I've been going on the assumption that this was due to USB mapping.