I just want to point out that the Loki love triangle is wonky. I know we all get the Sylvie stuff is odd, but this is about Don.
Loki's fixing-his-hair-and-coat-crush on Don, and Don's dropping-that-he's-single-crush are like a whole separate thing than Loki and Mobius's universe-altering-love.
Loki's reactions to Don are likely because of his feelings for Mobius, and Don's reactions show that Mobius has the capacity to like Loki in the future.
However, when Loki said "It's who" in that iconic scene, I think he was realizing that this man is Don, NOT Mobius. He wants to save the world for HIS Mobius, and that's the "who" he was talking about.
I really want to clarify my stance on this, because all the Loki's were shown to be very different. However, the one variant on Mobius we see still looks like Mobius. But they aren't the same.
And I don't think that the Loki we saw get his throne would ever really date Don, and I don't think our Mobius who let time pass would date a different Loki variant (unless his memories were wiped or something idk).
BUT I do think that if both the Loki and Mobius variants were different, it could work. Such as if there was a variant set that broke off on the 1893 date. And maybe the Lego variants of them.
Anyway, I'm just figuring out how to plan fanfics. Because I don't want every fic to end with "and then Loki came out of the tree and everything was all good." I want to explore multiple angles of how Lokius could come to pass.