The extractor tub is made of a fairly hard, transulcent plastic. I don't think it would colapse unless it got very hot. I would say the oil temperature was warm but not hot, hot.
I didn't see any sign of sludge on the tip of the tub when I pulled it out. Cutting an angle at the end of the tub sounds like a good idea. I might try that.
Sealing the dip stick tub also sounds like a good idea. Actually, I tried that with a rag. Duck tape will work a lot better. I'm not sure but I think I could hear air being sucked in by the extractor as though the pan was dry leading me to think the extractor tub was not into the oil. After failing to get oil out with extractor I reverted to the old fashion way of draining the oil. . . through the drain plug. It's a nuisance but I may have to continue doing that way. Also, I had removed the oil filter when I started using the evacuator. Do you suppose I should have left the oil filter in place before sucking out the oil?
Thanks all for your advice. Any more ideas are welcomed.