I asked Choice of Games support if they had a timeline for implementing a modified/new save system and this as the response I received.
"We know that there are a lot of changes people would like to see to the save system, and we do keep track of what they are and hope to implement many of them. It’s not something we have a specific timeline on. The issue with making these changes is not that we don’t want to do it - it’s that we’re a very small team with only five members.
Each of those members has different skills, and only one of us has the skills that would be necessary to implement these changes. He’s also the only person who can do a lot of other things, several of which are necessary in order for us to keep the company running and publishing games. So it’s difficult to find the time to make changes that - while we want to make them and we know that other people want them too - aren’t as essential as those other tasks. And it’s a significant time investment to make these kinds of changes to the save system - there are various issues, multiple possible ways to solve those issues (as you’ve noted), and other complications that aren’t always visible from the outside.
Deleting saves in particular is a feature that we really want to add, but for those reasons, it’s hard to say when it will happen, and we appreciate your patience."