Okay, patron and programmer here, just have to say;
First, the save compatibility issue really has to do with their original codebase for this game, which has old artwork, and which is being progressively phased out through updates- updates voted on by patrons. This update doesn't appear to have much added, but in fact the entire character of diane and her storyline was completely recoded, including her mini-game, and all redone artwork.
Basically when they started to expand the game they created a new codebase, and most content has been moved over. The only largely developed storylines on the old codebase were mom, aunt, and sister. I believe eve's content is also still on old codebase, but I'm not 100% sure on that. The issue being that it eats lots of time redoing large pieces you already did, and you won't necessarily approach them from a time-efficient perspective because what you choose to add each update is selected by your financial backers, meaning instead of taking time to just completely move over the codebase and continue developing, which would have been like .14 or .15 being released with zero new content, they are doing bits and pieces when they are told to, or when they can around what they are told to, which leads to updates where it feels like nothing happens, and updates where it feels like not as much as could have been done.
Ultimately, even with these complaints, I feel that this game has very high quality, a very consistant group of developers who appear to be adept at avoiding the dreaded burnout, keep fairly faithful to their timelines, and at least offer explanations for delays.