Since you have the luxury of having known good Lemo hardware at your disposal, maybe it's time to start troubleshooting using a known good chimney, cap, deck, etc.
Update:
I swapped out the glass which didn't help so before swapping parts with my others I took this one completely apart and gave every piece a good rinse. Let it dry and reassembled and problem fixed... No leaking whatsoever. It is easy to take apart and easy to put back together. Easy fix makes me happy!
It have been putting it on it's side intentionally and vaping it for ~4 hours with no problems.