A dumb lathe threading question

[Toolmaker51]

My solution would center on variety of threading inserts termed ''on-edge''...The issue between internal threading and boring hinge on deflection of the bar mass, where boring depends on the leading edge un-congested by chip interference and can be quite substantial depth of cut. Threading is more of a form tool operation involving far less metal per pass, to maintain smooth thread flanks, and generally slim proportion bars. Consequently, ID threading tools accommodate a greater range of bore diameters as there are varied combinations considering standard thread pitches and diameters, and more for proprietary combinations.

After decades of ID/OD threading, most have been accomplished with self-ground bits and bars, even ACME, Dardelet, and other buttress varieties. Access to tool & cutter or at least surface grinders helps, but definitely not essential. Even square threads, very uncommon to me past blackpowder gunsmithing, that took careful work all round.

I haven't seen full-form threading occur on conventional lathes. It wouldn't be my choice unless I could setup directly in front of the holder and centered over carriage to greatly minimize deflection.