It's so tricky because I feel if they are too lose then you end up dragging the top seals and they are more prone to deforming/peeling over. I guess I could run the heater pipe in first. I did it once that way it's just with the TGB it's a pain in the ass because unlike a 164 it has more heater connections so there are two sets of pipes that run and there's also an elbow that runs into the line right near the pump input so it either requires that elbow to come off (a real pain in the ass) or a second pair of hands up top to hold the pipe back far enough that you can get the pump in then once positioned to put it in and try to line it up. I think it would be a bit easier if you stabbed it first then before jacking but after the other bolts are run to pull that bolt out, insert it in then put it in then jack it up.

Another fear of mine was in warping the pump by having too much slack in the bolts and applying that much pressure on the pump. The tgb is heavy it's really easy to forget that when you are jacking up on the pump alone from the underside.

I do like your idea of letting it sit and settle while having a coffee (or beer).