The refractor in question is currently going modification.
Its current 2.5" focuser has a drawtube length of 90mm, and will allow focus with a bino sans GPC.
However, with the 2.6x gpc in place i run out of focus to where the focuser is fully racked out.
I can get it to focus by pulling the whole rig out and unseating it about 10mm or so but this is far from ideal.
I'd imagine a 2" diagonal and big 2" glass would be a similar situation, although i don't currently have any 2" eyepieces to test that.
The focuser on my scope has its limitations, so i'm upgrading it for something more robust ; not just for binoviewing, but for future imaging plans as well.