I do think its like another 2 reincarnation
It could work like that, but I also think they wanted to give her an advantage knowing the ending that would probably help her in the future.
Pretty sure the original villainness could figure out what was going on when she died (that her brother abandoned her and ML ended up with someone else) and catch what she didn't remember/see in her 1st life by being more careful in the 2nd life. MC has also been reffering to herself as the original villainness/"soul" and not their modern self for some reason so I don't see any reason for their modern self (i.e. isekai concept) to even exists in this manga.
I also think it's more interesting and realistic when the MC is NOT omnipotent and the ripple effects of changing the pasts keeps MC on their toes
Reading through all the chapters in one-go, MC doesn't even acknowledge her modern self after the beginning and there honestly isn't a need for it. Manga would've been completely fine and better if MC was just the original villainness who learned from her mistakes rather than being a different soul.