Thanks for your feedback!
To answer the points you made:
1. Prologue might make more sense to be simply text. Old games may times would do that, such as Zelda II.
Old games did that because it was cheapest in terms of ROM space and effort. I had the budget (and ambition) to go for this kind of feature, so I did.
Dracula II originally had a text-only prologue screen, but this was because there was little room in the FDS diskette for anything else. Simon's Quest did not change it in any manner, because they made the NES port of the game through the venue of least effort. They even copied inefficient stock I/O routines into the game to replace the FDS BIOS routines instead of creating optimized ones.
2. Speaking of, I really like how in that game it warped you back to the beginning. Would you be interested in adding that as an option at least? I know a lot of people didn't like that, but I love that as a feature in ZII. Or maybe it's something I could do.
I will keep that in mind. I don't personally see a good reason to add such an aggravating feature, considering how often deaths are caused by menial things like the water pits in towns.
3. Could you have it so that sprites go back to disappearing during text? Or at least make it optional? I don't think its the worst thing in the original, and it might be way more work than its worth to have an alternate solution.
It is an option already, but not provided in the vending machine. To get a custom ROM with this feature disabled, add &hideactors=1 to the vending machine URL that you get when the form is submitted.
4. Would you also be interested in giving the same treatment to CV1 and 3? 1 originally had saving in the FDS version, but not in the NTSC version. Saving in 3 would be nice in 3 too. Plus being able to press down and jump to fall down on stairs would be nice in both of them.
I have been considering Castlevania III, i.e. Akumajou Densetsu. But not Castlevania, because it does not have almost any dialog and I want to focus on translation patches. In any case, it is a lot of work to make something like this, so don't hold your breath. Might never happen.