That means that, at the same time every day, you need to submit your orders for the turn

This is not really true. You can submit your orders at any point during the 72 hour period. Most players submit conditional orders before the deadline, just in case - if all players submit and finalize their orders, the game will progress immediately.

I'm happy to play any non-live game that has phase lengths longer than 36 hours. (I'll copy/paste this message I suppose) But I do not play games that aren't Winner Takes All, as points per supply center encourages gameplay that is fundamentally different to the founding principles of Diplomacy. I would also prefer anonymous games to non-anonymous games.

I am on EDT, which I believe is -5 UTC, although I don't see why that matters for long phase length games.