I think I see your question: Since the plug does sit deep without the OEM spacer you want to protect the exposed wiring (as in the pics) with additional loom. I would say the connector pins are weatherproof using small grommets that fit the holes on the connector/plug. I would wrap it with additional electrical tape and call it good.
I agree about the heat shrink. After putting a few deutsch connectors together for other projects it's easy to see why OEM doesn't worry about "sealing" up the connector ends with heat shrink.
Skanjo you don't have the 12volt option on your refrigerator ?
or are you running a separate power wire for the Lance + power ?
i know Lance specifically states the OEM harness is not adequate
even on my Arctic Fox without the 12volt option ( just gas and 120v i ran a separate large + and - for the charging circuit