I find there is no "formula" for fitting a bike. It comes from knowing your body and the position you want to be in. But, you gotta start somewhere.
Does your crotch clear the frame? I don't know too many who'd NOT like to clear it.
Where do you like your bars in relation to the seat?
What kind of bars do you use?
What is your best riding position, straight up, bent over 60,45, 30 degrees?
All this help you choose the length of the top tube. Being tall and having ridden on short TT's for most of my life until the last 10 years. . . I can say I would absolutely take a frame with a longer TT, and use a shorter stem rather than throw a long stem on a too short TT frame. The feel is totally different, from being "with" the bike, as opposed to being on top of the front end. It's a matter of balance.
Top tube length and head tube length(the ability to get the bars where you want them), are often under considered when getting a new frame, then they scramble after the fact to get the bars up or out or in.
Give it a lot of consideration. The actual frame size will likely be in the ballpark if those two factors fit you. If not, go custom
