Don't know if you'd have to worry too much. Yes, H1B is dual intent, but that only means you are not required to prove you have no intent to immigrate. It doesn't mean you are assumed to want to immigrate simply on the basis of the H1B, regardless of your individual circumstances.
If you can demonstrate you have no intent to immigrate, then you should be covered for either
TN or H1B.
Another example, cohabitating partners can get B-2 status, which requires non-immigrant intent, on the basis of their primary partner's H1B. If H1B always equated to immigrant intent, such B-2 statuses would never be allowed as it would be assumed the B-2 partner was intending to immigrate as well.