I was interested to see Paul Brodie attaching seat stays with silver, without really a fillet, just using the kind that flows in. My understanding is that silver is the strongest way to do that kind of joint. But if you don't have a decent fillet, or some surface area such as is provided by a lug, a "flowed-in" joint like that will not be as strong as a weld or a fillet braze, i.e. will it ultimately fail before the parent tube does.

On another video (Cobra Framebuilding) he attached a SS bridge like that, and then I think IIRC redid it because people expressed concerns about strength. I'm sure it's fine for a bridge tube, and if Brodie attaches SS like that, also fine for those, because he has never had a failure. But I suspect it isn't as strong as the parent metal. I could test it but my brazing skills suck too much and I only have a MAPP so I don't think it would tell us much useful