There's no way to solve the Helga/Meloni puzzle without a wish.
And the save file thing is a limitation of HTML and Twine, so it will be always tied to your browser cache, unfortunately.
It will get one more patch that fixes a bug or two that were preventing some content from being accessed (so kind of getting new content), but there will be no further content updates. Just occasional patches.
I'm currently finalizing the first Version Release of my next game for Patreon supporters, so that will show up here in around 6 weeks (it's less an adventure game and more a pseudo chat-bot style experience).
After a few updates to that game, I'll begin work on another text adventure like this one, with a future sequel to Enter the Expansion Mansion planned, as well.
All of them stem from the Devil in the Library. Many off the wishes will either have no immediate effect but will add an epilogue to the story as long as you don't get a "bad" ending. Others will send you directly into a new ending.
Some wishes are only available if you've explored enough or the wife is big enough, so do plenty of exploring before you make your wish.