Your first reply is that we can discuss the resurrection question without invoking the concept of a 'miracle'; but I think the example you give is seems flawed in a number of ways relevant to the argument for the resurrection of Jesus (RoJ) and I think you may be smuggling in a 'miracle' through the back door when we get to RoJ.
"All one needs is to look for evidence that a person was alive at T1, dead at T2, and then alive again at T3. If a person begins to live after having been dead, that is resurrection (at least in a minimal sense, if not the robust eschatological sense assumed in Christian theology). And one can look for evidence of that type of occurrence without ever considering whether it constitutes a “miracle” or whether it is, in some sense, “supernatural”."
Its possible that I could agree with your statement, though it's going to depend on what you mean by 'resurrection'. This is going to be related to what you talk about in your second reply however, because these things are interrelated.
For instance, I have no problem thinking a 'resurrection occurred' after reading about a medical procedure where a person was alive at T1, declared dead at T2, and then alive again at T3 - with only a specified minimal amount of time passing between T2 and T3; or perhaps some kind of explicable technology keeping someone in a kind of biological stasis between an extended T2 and T3 - but even then it'd require some kind of additional explanation and pretty good evidence for the latter occurrence, since we have no knowledge or experience of such technology working.
The details of T1, T2, and T3 matter. Given what we know of the world today, it's not too surprising to hear of the sequence of T1-T3 if the time frame is short between T2 and T3. But then I wonder if such an account counts as a 'resurrection' in your view?
This is because as many apologists argue during debates about RoJ, the thesis is not that "Jesus rose from the dead naturally; but rather that god rose Jesus from the dead'". In which case, a resurrection only occurs when 'god raises a person from the dead' - then I think you are necessarily invoking a miracle when you're trying to prove that someone was 'resurrected' in this sense.
This isn't just a fact about resurrections, it's about things that wildly violate our background knowledge. God, if one exists, doesn't just raise people from the dead. He could, presumably, go about doing that around the world today, if he so wanted. So even on granting theism, our background knowledge of god raising people from the dead is extremely low.
A parallel example would be about someone being on earth at T1, being on the moon at T2, and then being back on earth again at T3. We have an instance of multiple people fitting that criteria in our history, but again the details of time difference between T1, T2, and T3 matter here. If I told you I was on Earth at 1PM EST 5/10/2019, and was on the moon at 1:05PM EST 5/10/2019, and then back on Earth again at 1:10PM EST 5/10/2019 - you'd require some pretty extreme evidence of such a thing because our background knowledge about how one travels to the moon, the time it takes to get there, and who gets to go there is very specific. If I tried to assert that god or aliens transported me there in a fraction of the time it'd take to make the trip as a human, doesn't really decrease the amount or quality of evidence we'd need to justify a belief in such a thing.
This is what I mean when I say our experience of the present is used to interpret the past; not some nonsensical principle that "for X to be a legitimate explanation of a past event, X must be presently observable (i.e. “regularly and verifiably in the present day”)."
After all, if we had regular contact with aliens, or we sufficiently advanced our technology to Star Trek levels, it would not at all require much evidence to believe that moon sequence I discussed above.
So it is with claims about resurrections and our current experience of the world. I have no problem with a resurrection being investigated between T1-T3, in fact I may well accept some of those claims (if resurrection doesn't by definition require god's actions), for specific times between T2 and T3. But when we get to the argument for RoJ, the time between T2 and T3 is sufficiently large that for 'resurrection' to be the best explanation of the evidence we have, it's going to take a lot more evidence than what we have in the gospels + Christian bible to believe it as the most probable thing that occurred.