It's been >10 years since I made an Arkansas call (started making metal reed calls), so hopefully a few better experts will come along that may be able to offer specific advice. For them to do so, you should probably post pictures of a current insert and reed, assembled and apart, from a few angles.
In the meantime... it is a long learning curve that only gets accomplished through lots of tweaking, failure, and persistence. A public jig can get you to decent sound more quickly, but you probably miss a few lessons that way and progressing from there will likely take longer. I always recommended starting by making a flat jig out of hardwood - that allows a consistent height/flat tone board and wedge, but you freehand the curve little by little and learn effects. Make a bunch of flat inserts at once so you can trial different things on the curve.
I also think there is value in taking your 2-3 favorite/best sounding calls and taking extensive measurements and observations on them individually and then comparing them. Can you identify differences that might contribute to differences in sound or how much air they require, etc.? Or did they arrive at similar sounds with notably different tone boards and channels? Even make hardwood jigs based on them and then make a few trial inserts off each. What have you learned? And then back to freehanding some of your flat inserts to put new knowledge to practice. Put your freehand inserts into the jigs you made and hypothesize on why they sound different from each other and from your favorites. Then tweak more and try to prove your hypothesis.
An iterative process that yields a good bucket of firestarter before it yields anything (repeatable) that will call a duck.