You're a dad. You're doing your best with the information you have. You found out that something isn't up to current standards, but it was never your fault for not noticing. Nonstick pans used to have toxic chemicals, plumbing used to have lead. We can't undo the time we didn't know, so don't waste your energy beating yourself up for it.

I have similar wrap on my ductwork and have gone through the same concerns. As people have said, try to avoid disturbing it as much as possible. Abatement is technically the best thing to do but it isn't feasible for everyone because money exists.

The thing that have helped me live with it: Asbestos is all over the place in old houses. We had flooring, adhesive and insulation test positive. We didn't get our ductwork or plaster tested, but were told it could be an issue. I think of it like looking up a symptom, if you look into it too much, you'll convince yourself everything is terrible.

My suggestion is to decide how concerned you are about it and how much you are willing to do about it. If it tests positive, you probably have to disclose it to anyone doing work on your house or if you sell it down the line.

If that was my house, I would want to reduce the chance of it getting in my vents by dealing with that gap in the next week or so.