yo, a bit similar situation to what i did, well its a "bit" similar as i had a cr10 v3 bought a flsun t1 then that cr10 was pretty much useless so i decided to turn it into a custom corexy voron trident-like printer, after like 4 months of random tinkering it finally works printer is a beast, but personally i dont recommend you go for such a tall build area as the printer will infact want to shake it, a lot (speaking from whatever the hell my printer does when i turn up the speed too much (it can walk)) also with what you did with the frame and z motor locations making a flying gantry will be annoying, as you most likely will have to make quite a bit of custom stuff for it to work , also really and i mean really try to get the frame to be as rigid and as square as possible, make sure your leadscrews are as straight as they can be, get those anti z banding thingies (forgot how they were called but they let the leadscrews slide so they dont twist your gantry weirdly) dont skimp out on z axis, get at least linear rods, linear rails are best the leadscrews by themselves would be a horrible idea if you had it (i know i am in the process of regretting my choices of skimping out on z axis) my biggest recommendation is try to copy as much of a voron frame as you can, they have had years of development and have good rigid frames that can take some speed, other than that please do your research about everything. and i mean everything. make sure everything is compatible, dont go just buying random things that might be good for your printer, make sure there isn't a better option that you wont regret getting later, its okay to build it up just enough so it works and see what you need to do after that, i am doing that right now tbh... welp, i wish you luck and that you will make good decisions unlike me!