Sections 501.15(D)(3) and 501.15(E)(2) were based on a product that was proposed, but not marketed; i.e., “gas-blocked” cable. Basically, cable manufacturers don’t want to make what UL wants to test. The concept is still valid, but no one certifies it.
That said, in order to treat the multiconductor cable as a single conductor at the boundary, the installation you described would be an application of 501.15(D)(2), Exception. BTW, if the cable has "a gas/vaportight continuous sheath", only the end of the cable actually in the Division 1, location is required to be sealed. Check the UL "White Book" for cables that meet that criterion.
Robert B. Alexander, P.E.
"I know that you believe you understand what you think the NEC says, but I am not sure you realize that what you read is not what it means.” (Corollary to Charlie’s Rule)