That's some pretty nasty rot you got going there...but I see what you're saying.

In the case of rust like that, I would not lift by the pinch weld. But a block of wood will prevent you from collapsing that moulded rail looking piece, like I've seen happen on completely rust free cars. I.E. mine. Lol

I can upload pics later, but mine are almost minty compared to that, and I'll show where my moulded rail started to collapse because of previous idiot owners.