part of the farsz
In the stuffing, though I don't use egg. With stuffed things, I've always found that a loose consistency works better, with breadcrumbs (I tend to use fresh ones, British style rather than continental bulka tarta) to soak up liquid. The cheese will put out oil as it cooks and it's a shame to waste that.
But standing up is also fine
I've done that too but had better results with them lying down.