I don't think they stole my idea, just came up with it at about the same time as I did.
Too easy to make to patent. I thought about selling them through one of the big archery supply houses but being retired I am done with actually "having to work" and would rather make bows, flintlock rifles and just give the gizmos away.
I have given away between 150 and 200 of them so far but don't give them to everyone who asks for one. I give most of them away unsolicited to people who post pictures of their first tillering job and it is obvious they need some help.
Early on I gave away a bunch to people who were"thinking" about making a bow. I suspect few of these gizmos ever got used.
Now I only give a gizmo to a person who is actively working on a selfbow and often to a young person who lacks the equipment to make their own.