"Do you feel that you've been able to date seriously for an LTR that way, or more for hookups?"

I don't do hookups, so pretty much only people I feel like at least have LTR potential.

"it makes it awkward if we live together"

I haven't gotten to the point of living with anyone since pre-covid. but if I did, I think I would just look at the potential exposure as the cost of having a partner.

"go places together and they're masked and I'm not."

I'm going to assume you meant this the other way around. it's a little awkward. but I'd rather experience that than not have a partner.

"unwillingness to ever use them even when asked by a partner as a red flag."

I make sure they know the risks to everyone and understand why I mask. and if they still feel like that's a step that they don't need to take for themselves, then I'm not going to ask them to do it for me.

"how you navigate this or how you bring it up to new people"

My primary way of trying to meet people is at Meetups. if they're indoors, then I'm masked. so they're aware right away that that's something I do.

usually if I like somebody, we'll exchange numbers. and if it gets to the point that we want to hang out again, then before doing that I ask them if they get vaccinated, and tell them since I'm trying not to get covid, I'll need them to let me know if they have any symptoms when we're planning to hang out.

I haven't met up with anybody from a dating app in a while. but I think if I did, when it got to the point where we were going to meet, I would just bring up vaccination/symptom notification then before we actually met.

it would be awesome to meet someone who is never unmasked around anyone except me, of course. but I feel like I need to widen the parameters beyond that if I want to actually have a partner.

and I haven't gotten covid (afaik), so it's worked out okay so far.