I wonder what takes so long to dev those patches. Not trying to stir up the pot. Just actually wondering. In the last 4 months, I coded and released two large web projects. I know it isnt the same, but still... I can't see how coding for at least 6 hours a day (its his work at the end). 4 months. Lets say its around 400 hours of coding in 4 months. There is something weird or wrong in his schedule. I have no idea where he lives too or if this is his job or not. I am just an weirdo in the internet that likes this game... At least I have BBSmv2 to enjoy for now.
I imagine it depends on his skill set, but in my experience with modding in RenPy so far it's not the coding or the writing that takes the majority of the time. The time sink is Daz. You can speed that up to some degree if you have a fast computer but that only affects render times, not set up time. It should get faster with practice but it still takes awhile to do the posing and adjust lighting for each scene.
If you have to optimize the scene to reduce VRAM utilization it takes even more time. I sometimes spent more than 1 hour per image just setting up the scene and then more like 20 minutes actually rendering it. This was with a low end system so my current one could render it a lot faster but that would not help with set up.
Personally, I think his focus on using layers and multiple outfits for the same scene is probably making the coding more complicated and that might be extending development time significantly. I played around with using multiple outfits for the same scenes before I decided it was not worth the hassle. I'll use a different outfit for an entirely new scene but I'll never do the exact same scene with 2 different outfits.