I think its the c-move thats the prob so maybe set minmax and raise the model by a couple of quants untill it becomes unstuck.(the poly ovoid shape adds another couple of quants to the initial height of the model but can be tweaked with origin shifts in the model and z axis tweaking)
Also use c-rotate to pan, that helps a lot with this issue but its one of the reasons I went to full modell levels.

A possible solution is to have a non complex corner (invisible) over the seams like an angled single block placed just above the seams to wallk over.