Is it possible to enable FCC Mode on an Iflight Alpha A85 with a Caddx Nebula Digital HD System? And if possible would it run too hot?

Yes, the Vista will show up as a usb drive when you connect it to your computer while the battery is connected and you can put the txt file on that. I've been running 1200mW on a naked Vista for a year and haven't had any issues, so yours with a heatsink should be fine.

How can I do that? What text file to put in what location. Please help. Thank you very much.