thanks for all the inputs. learnt a lot and got some clear idea on what to do. looks like:
1. would still like to go with low-stack threaded HS pro'ly sans-washer + hand-filing meditation where applicable. i've done my diligence searching some 'ternet, to come up with known-sub-33mm-stack HSs
Sch-mano Ultegra(600) 33mm, 105 31mm, DA7600 31mm, CK GripNut 33mm on high-price or rare side & Tange OEMs including Falcon, Levin CDC, Passage all around 31mm on low money aka readily available side. goal is taking 3-4mm out of the height, than i should be within safe margin of 2 - 3mm ish.
2. Inicycle seems a slick option, however 1/8 stem & peripherals are not really my taste. maybe one day.
3. facing/machining headtube ends or replacing steerer tube option sounds straight forward, but not this time. stepping out to even Trade Joe's for grocery still spooks me out. gonna have to stay put low for a while, and building a bike is kinda perfect excuse 'not have to go out'. sigh
Last edited by orangeology; 07-11-20 at 03:51 PM.