That is ultimately my plan. Gonna cut a screw down as a stud and put the
same resin in the there and cure the whole thing in a UV chamber, should
get rid of any issues with the square edges in the initial hole.

I tested a piece to destruction, it broke at the collet slits when I side
loaded it too much on the lathe, which is a fair bit and not anything id
expect in use. This is with a exterior collet I made to fit this collet, I
have yet to test the strength of the threads, i will do so next. Torque it
down hard with some washers in between and see how much it takes to strip
it out.