Rey, we know there was a lot of work done.
With that said I thought this was going to meet the desires of all the three different size folks?
see thread where that was discussed.
I do see that you said the 15mm extention route was $3 less then making 30/45mm tubes. I think if the shop was pressed the 15mm extention could be had for not much more if it brought in the volume.
Congrats on the new Ali Ex store.
Machine shops will want big $$$$$ if they have nothing to loose. if they price them selves out of the business by charging too much for 15mm extentions then that is their call, but let them decide if they make more money on more volume or less.
I am confident you can explain it to them that they will make more money selling more units.
I know you did your best.