you certainly jumped in the deep end there, I built racks to practice on, then some city bike frames. but then I have replaced my front teeth 3 times…
why didn't you use a 33mm zona seatube?you'd have been able to use a 31,6 seatpost with no shimming.
Lugs are available for mtb angles and tubing.
long shen 108 if I remember right,
it's a 35mm dt, 32mm tt and st.
They aren't suited for a susp fork, unless you're running 25mm of travel.
peter at ceeway has them.
for a rigid bike they work with a bit of tweaking.
Using them on this 650b bikepacking fully rigid lugged custom steel bike I'm building.
(do I get a prize for the niche-combo?)
Bilaminate headtube, so that's why the lugs don't go arund the headtube , it's 1.5mm so it's not a problem.
working with Calgary framebag builder Scott, of Porcelain rocket, so it's a canaditalian collaboration.