Dschwan
WKR
For anyone interested, I posted the Bitzenburger fletching jig angle setter on Thingivers. I used to CNC these out of aluminum in my garage years ago and sell them as a set. These will only do a left and right offset, not a helical.
https://www.thingiverse.com/thing:7301200
https://www.thingiverse.com/thing:7301200