I would ignore anything Michael Dorn did, because I can't stand Worf. First he ate TNG, then he ate DS9. I wouldn't consider his little project to be any sort of canon whatsoever.
There are earlier parts of the Trek TV and movie productions I don't consider canon, either - ST V, and any movies after First Contact. The only
reason I reluctantly accept that movie is because I really like the character of Lily, and the movie was referenced in a Voyager episode. I accept NONE of the Enterprise series as canon.
But that's the beauty of having so much choice. Some bits of the Trek universe I can enjoy as simply one more alternate universe of "what if it had happened this
way"... and some of it I can completely ignore just because I think it was so poorly done that it doesn't deserve ANY place in the Trek universe.
BTW, I read the book that the Garak actor wrote. It was terrific, and I say that as someone who doesn't really care for Cardassians or DS9 in general. But I always found Garak an intriguing character.