newwin / letterboxing rounding with subpixels is off

I'd rather be too tall/wide than too short

I have meant to run a swath of tests (different res/system scalings etc) on my laptop. Anyway, fired up the laptop for the first time since Portugal and am greeted with this

3840 x 2160 native res
system scaling is 175%
note the diff in TB14 vs 13.5 - the inner window value
anyway - LBing and newwin have decided that I should be 1400 x 899

pics/log

TB 14

TB 13.5.7

cc @ma1 @pierov

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information