Perhaps not an issue as window was for light not ventilation; have mvhr for that .
Not sure why I discounted having the bath going width ways . Does remove pinch point issue ; also allows again for larger shower tray . Some small areas of floor won’t have ufh in this setup - small price to pay I think ...
There are other considerations. SWMBO has chosen a recessed mirrored wall unit that’s over a metre long ....?