I've generated threading macros using G33 and very modest depth/pass values for 16,24 and 32tpi, put them in the lathe macro file.
User is prompted for length of thread.
My lathe in this case is a Sherline, quite small but rigid. Have cut all in Aluminum, mild steel and some type of Stainless steel with good
results. Anyone wanting to add these to their grblgru macros PM me, thanks.