That's a good solution, thanks for letting us know how it turned out. When you programmed all 6 channels did you use a different coin for each channel's programming and not the same coin for all 6 channels? (I think that is what you are saying). By using 6 different half-dollar coins to do the programming it might make the acceptance even better since there could be minor variations in each coin's metallic property.
I didn't know that about the mint still making them available, I guess the premium charged is due to them being uncirculated, for coin collector purposes I guess. Helping to pay down the National Debt!