I am almost 6ft tall but I have a 31ish pants inseam which equates to a 32/33 cycling inseam and a very long torso. My ideal size if you use a sizing calculator is 54 which is too small and of course the calculator tells me others sizes included 56 through 58 . I have found in a production bike which is all I can afford a 56 more or less fits me as long as I use a 100 or 110 mm stem length . A 57 can work well with a 90 mm stem and my only 58cm bike has what amounts to a near perfect top tube but the stand over height is not ideal .
In the near future I would love to be able to afford a custom build which I am saving for , but it’s not going to happen any time soon.