I can't give a timeframe. It's probably going to be slower than my previous updates though.
I'm at the point where the VN splits into three different endings so there's three times more work involved.
I'm also looking to make the next update the final one and complete the story, so again, lots more work to do since it will probably be a bigger update than usual.
I don't want to release updates for one particular path at a time since that would just confuse people.
If they were to download it and not be on that particular path, there wouldn't be any updated material for them, so I'm working on all three endings simultaneously.
Finally, just to give myself even more work, I plan to add bonus scenes to show what was happening in some of the other rooms while you were playing.
Damn! After reading that back it does sound like a shitload of work left to do!

A lot of the bonus scenes have already been rendered.
All ending scenes from the boxed-in building have been completed.