I wish he would stop reworking old content and just focus on new stuff. It sucks when you either have to restart your game or miss changes that you didnt get to see. Just get it right the first time lol.
The thing is that during the voting for 0.5.7.0 content what won was the rework + balance part. So him working on stuff like weapon weaknesses, remaking images, making enemies tougher, enabling the player to get a lot of talent points for free and so on makes sense. Now I'm not sure if 0.5.6.5-0.5.7.5 will all be about that since Chyos will probably keep working on it until he's pretty happy. It's been mentioned that the next big thing that needs to happen is Kirlic from what I remember since that area and it's people needs to be introduced to progress a lot of stuff for many characters and their quest lines. For 0.5.8.0 we'll get Kate + Claire content with the focus of them going to Kirlic, however it will first be about the move and them stopping at an Inn Claire mentioned. After that in 0.5.9.0 we'll probably get Penny content focused around the farmland she lost to the Coldstone family. After this it's a bit up in the air what we'll get but mostly the content order is voted for by the backers.
Most likely it will be any of the following: Arianna + cult, Bianca + Gavina + dark elves + goblins, Kirlic introduction or Julia marriage + Yasmine visits + Giron repeatable tasks to gain trust and easier lvling.
Also the missable new stuff is usually just minor stuff. Like all the image remaking are usually always available the thing you miss is some dialogue changes, unless their quest specific images, but don't think that's worth replaying for.