Having played more, it feels like H level is easier to raise? It might be that I know how to use the Magazines now, it felt like it went faster than when I was relying on Cassia and stripping to gain Lust.
The requirement to reach level 7 has changed, but not in a way that adresses the issue I brought up. It requires 2 character with H level 5, which is always already achieved because level 5 needs 4 H level 5 to be reached. Lowering the number of girls is not a solution anyways: you can't choose which customer shows up so their H level grows steadily. By the time I reached 4 H level 5, I had two more at level 4 and only the customers I barred from shopping were under level 2.
Even if level 5 was easy to achieve, it feels bad to unlock pregnancy after reaching the end of the progression with these characters. It would feel better if there were H levels beyond 5 or if Zhara needed 4 H level 3 instead.
There is a small bug when you unlock pregnancy: you can't impregnate Zhara in the same interaction, the impreg attempts counter shows up but stays at 2, in your profile the Fertility perk doesn't activate until the next day.