Yes I play that in 20mm, to be honest and without my Bias hat on. I do prefer PBI V3 and beyond as my WW2 game of choice. Especially after we found It does scale up, with figure sizes and using bigger tables.
Do you play with the same scale distance as 20mm on the board ?
Maybe in 15mm with the scale ranges and the 6 x 4 board it might play better ?
Miles.