245/40/20 on a 10" so has a huge stretch.
My B14's have had the rear adjusters deleted with the proper delete kit from Transporter HQ and the front is maxed out with the machined top mount. Both of these mods gave my B14s another 10-15mm drop, but bare in mind that my van is heavy with all my work kit and fully boarded out with 18mm ply, so it will naturally sit lower than any other T6 with the same mods.
It still drives the same as it did with the B14s on max drop. Stiff yes, but certainly not uncomfortable for me. The only drawback is I cannot get on some drives and speed humps are a bit of a pain because I need to go very slow.
Just noticed you are from Leicestershire, where about's?