image_size vs window_spec

The default image_size appears to be 1024 for all models, but the window spec for T, S & B+ appear to be optimimal for image sizes that are multiples of 224 (ie 896 or 1120 would be better), only the L will work with multiples of 256 w/ extra padding overhead for the windowing...

EDIT: for L, that should have read 'w/o' 'without extra padding overhead'

Curious if there was a reason for this?