Can't speak for tradgang but definitely still a couple guys on Leatherwall doin it.Wear a good dust mask if you grind them yourself, there used to be guys out there that would grind them for you either for a fee or some guys would grind both wings and give you back the feathers from one of them and keep the feathers from the other wing. Do a search on tradgang
I built a burner really cheap- you need to buy an old model train controller from eBay which was cheap. Look on YouTube for the video. I’d give you a link but I think you’ll find it on diy sportsman? You’ll glue your feathers to the shaft and get the wire red hot and spin them. Turns out perfectly profiled and takes five seconds per shaft. But beware- burning feathers inside will get your wife raging out because it’s really nasty smelling. I do it outside.I kept some turkey flight feathers from this spring any tips for using them as fletchings?