Good question!
My current release plan is to get v0.18 out in early/mid November and v0.19 out in mid/late December. Thus, I will begin working on v0.20 in late December, but I will not be releasing it until later.
Due to the scope of v0.20, it will take longer than the usual 4-6 weeks to turn around. It might take me 3 to 6 months to complete once I start working on it. So earliest it will come out, in my estimation, would be March 2025.
Of the 30 girls to add, I have already created 18. So, I do work on what I'm going to add to the v0.20 while working on the updates I'm releasing. The reason it's going to take so long post v0.19 to release v0.20 is that I want the 30 new girls to be at the same standard as the rest. That means I'll need to do the following events: meeting them event, 2 repeatable sex scene, home event. Multiplied out by 30 girls that's 120 events, with 60 repeatable sex scenes. MUCH larger than my usual updates!
Hope that answers your question! I'm currently working on v0.18, getting small events done, and I'm looking forward to all the updates I will be getting out to you all.
Cheers!