I feel your pain Abbo! Have you considered the possibility of lowering the o/s only with a single lowering block to gain the extension travel? Mulfab do a 20mm thick lowering block but from their
picture you can’t tell if the locating hole and dowel are in line or staggered. If you were only fitting one then they would need to be inline otherwise the axle would end up further forward on one side. Maybe worth a call to check, or perhaps it’s an item Simon could help you with? It would also need longer u-bolts too.
Perhaps it’s something that could be experimented with first to check the results. Quickly sandwich in any old spacer between the axle and spring to see the effect, but obviously don’t drive it like that…..
