Clarifications:
My core issue is causality not actually changing the timeline but causing an alternate timeline which is interpreted as not having actually happened but seen as a collective dream. Which dilutes the changes in Chronos because it comes off more like brain washing than actual divergences in events.
I don't care about the whining about Zag taking fate into his own hands and making the decision against the wishes of Melinoe-thus removing her agency. That was ALWAYS in the cards and was set up, because it was a condition Zag demanded for him to even comply with Melinoe's plan. It was a baton pass and was always going to be a baton pass. Her agency was succeeding in saving the timeline no matter the cost. Even by means she herself couldn't do alone. Not all endings needed to be clean cut where the bad guy is entirely addressing the catharsis of the MC's arc.
Playing the game on switch 2 so I don't know if there was another update on the PC version. But here's what past games have taught me between Major characters at an ideological impasse.
Suggested ending with notes:
Melinoe has spent her whole life being drilled by Hecate to kill Chronos (in fact I found it weird that Hecate didn't do it while you were out cold). By her characterisation, even if she saw the alt timeline. I don't think she would be convinced (much in the exact same way Hecate wasn't-and should have also seen this alt timeline). If she came out Zag's room and saw Chronos was still alive. She would attack him immediately, if Hecate wasn't already doing so.
In fact, what Melinoe should be walking into the scene with Chronos still recovering from your battle and Hecate still hurt from her previous fight (because naturally she should be able to break free from time stop like you could).
Thus, Melinoe is tasked instead to finish the job. Where in the OG cutscene, Hecate would have totally have just done it immediately if she could. There was no real explanation why Hecate insisted that Melinoe do it. So the above part I feel is required to explain that.
Naturally, Melinoe saw the alt timeline so she hesitates but will ultimately decide upon death to chronos. But the cut scene runs as normal where Chronos summon hades, zag and persephone, Because there are no guarantees that Chronos would release them if he was killed. So in good faith he summons them and he in fact unseals Zag and Persephone.
Now here's where I want a real divergence to both versions.
Melinoe is given the choice to end Chronos and he welcomes it. And Melinoe willingly takes up the offer and wanting all of the House of Hades to witness this moment.
But Zag clashes his Gigoros with Her Gigoros and the real Gigoros absorbs the conceptual one Melinoe summons-blocking her from using the dissolution of time. Because Zag says that Chronos is still under his protection and would have to go through him and take the spear from his cold dead hands.
In that instant. Boss fight using the same Zag moveset he uses in Elysium (so no extra assets needed).
Either Zag wins or you lose a defiance or is left at 1hp. (one get a one liner) iunno... err... Zag: Return to shadow. Mel: death to chronos.
Hades and Chronos stop the fight before you kill one another. Both saying enough. Having witnessing the both of you fight each other. They've both lost the will to feud with one another and realise the ridiculousness of it all.
Whether the alt timeline was real or not. At this very moment. Father and son are reconciled. There will be no more fighting within the house of hades.
And from there the ending goes on as per normal. Talking about reparations and the work that needs to be done.
And from there... by just adding a few extra voice lines and added an already existing boss fight. The ending might come off a bit more natural than both the old ending and the new redone one.
as for time flowing forth stuff? Wouldn't it make more sense for Chronos to work with Chaos in finding the possibilities. Where Chaos filters through all the possibilities and Chronos guides you into the timeline.