Just to give you some numbers, Day 1 for each of the girls had slightly under 50 screens. Their Day 2 has 100+. The same applies to the length of the text and the nature of their spicy scenes, which now have more positions and phases. For example, with Tessa, you have foreplay nursing hj (Tess giving), complete bj scene (Tess receiving), cuddling, and finally, shared shower. It is fully with my original idea that getting closer to each of the girls also means you are spending more time with them, both sexually and just doing something else together.
But the main reason is simply the sheer size of the R3 as a whole. R4 and onwards will be a lot smaller. Hopefully released in two-month cycles.