Changing to larger tires shouldn't make the axle start hitting the bumpstop, nor should cranking at the front.
Your springs are far too new for the axle to hit the bumpstop more than rarely and under unusual circumstances.
I'd suggest add-a-leaves regardless. Calmini or SLR are the way to go, SLR is easier to install.

Brent
_________________________

Tip: see if your question has already been answered before asking it. Try our handy-dandy search tool!