Two Questions:

1. Does this change require an OTR Regen? I'm guessing so.
2. Will this cause the user to get prompted to regen their OTRs? I'm unfamiliar with how that code works.

Would require a regen. Will not crash with older OTR, just the same behavior will exist (invisible water).
Will not auto prompt for this.

In the past we handled this (xml changes in patch release) by making a callout in the changelog that a regen will be required for specific fixes.

Works for me, was just curious about the OTR situation. For the record, I tested a version before this patch and this patch, and this did fix Morpha's water but the titlecard looks the same on both. Is this one of those situations where the incorrect size didn't visually mess anything up or was Morpha's titlecard just unaffected?

Oh wait I understand it now, the titlecard extraction being wrong is why the water was broken, nevermind.

That's because we additionally extract the title cards separately as split up textures (one for each language). So the ones I'm adjusting are technically unused in SoH because of our design changes.