>>2950757
My basic plan is to weld up a 4 legged table out of square HSS. probably 16 gauge, 1.5"x1.5".
a lot of jack options seem to be around 20" or so. I'd figure I'd make it at the highest with a worktop at ~34"

my current best idea is to steal this guy's design. This is welding table with a hydraulic long-ram jack. This would be too tall, the jacks are like 24" minimum.
But I can use this same concept with an RV scissor jack to adjust the height (20" of range) and then pin the telescoping legs to stay there.
I think this is a pretty good idea. I don't know exactly how I'd mount the jack to it.
https://www.harborfreight.com/2-1-2-half-ton-trailer-stabilizer-jack-96406.html
for mounting the jack, I don't know if bar stock is sufficiently rigid. Maybe i'd need to drill holes in some square tubing and bolt the top and bottom of the jack to it.
I also don't know how much of a pain in the ass it'll be to do the telescoping legs. it seems simple enough but maybe there's a lot of slop, plus the weld beads inside the tube.
and i'd want to put like a plywood sheet on the top of it as a work surface. I don't really know how I'd attach this without bolting through into the tubing which I think will look like shit.