My opinion as a Submariner:

The existence of the Polaris tartan is one of the things that got me interested in wearing the kilt and having an option [yet to find a single drop of scottish blood in 400+ years of family tree] of a tartan to wear.
I served on Real Boats not boomers and was never stationed nor visited Holy Loch so I am still convincing myself to get a Polaris Tartan [rarity and price aside]. If SubVets or the Navy [or the Royal Navy for that matter] themselves were to make it the "official" tartan of the Submarine force I would feel better about getting it myself.
The comparison between the Polaris and the Edzel/ US Navy is comperable to the comparison between the Special Forces/ US Army [granted the Special Forces tartan does have restrictions]. You can wear and respect/ represent the "more restrictive" tartan you just must be prepared for more attention/ questions from those in the know about the history of the tartan.

A lot of it comes down to "levels of fraternity." There is in this case the general fraternity of being in the Navy , then the more exclusive fraternity of the Submarine force, then within that the subset of Boomer [missile submarines for you land lubbers], and finally within that those that served on Polaris class boats or where stationed at Holy Loch which has its own tartan.
A comparable example from one of the editors at the Rocky Mtn. New who is a Vietnam era Army vet. but served as a journalist at West Point who stated that he is not "in the club" compared to combat vets who in turn are not in "the club" compared to POWs such a McCain.

Sorry for rambling but this, as I am sure you are aware, is a regular topic with regard to Military tartans and I wanted to give my perspective. As others have said you can do what you choose you just need to be prepared to answer the questions that arise.

As a couple of the other bubbleheads have mentioned the discussion of wearing dolphins [or a fouled anchor, or the eagle, globe & anchor, or a Ranger Tab] as a kilt pin or a broach is a more sensitive discussion.