weathertight bulkhead options with LFMC fitting on one side, EMT (or multi-conductor cable) on the other side?

[don_resqcapt19]

Ok so say you have Rob's running thread idea. I see several options from there:

1. But a box on the inside and the outside with locknuts. What could be wrong with that?

2. What about a RGS coupling and a 90 degree flex/sealtight connector on that? IS that one of those silly academic things where we cant thread a connector into a coupling? I just did that today LOL.

1)I though the whole purpose if this thread was to reduce the costs of the penetration. I would expect the labor and material to provide boxes on each side would far exceed the cost of an actual bulkhead fitting.
2) A coupling on the running thread? That is specifically prohibited in 344.42(B).