One improvement that HS2 had over HS1 is the acknowledgement of futa fans. The only way to get futa on HS1 was either through the model swapper, which makes the futa larger and looks odd since they're essentially female fitted on male skeleton, or studio. Dong accessories exist, but the futa would still play the female role.
Koikatsu was the next best thing, as there's a mod that allows transgender loading, as in loading female on male slot in studio and vice versa, but only HS2 so far that adds the feature built in. Strangely, you still can't transgender load on the studio, despite the main game allowing futa as male.
ILLUSION in general seems to not really like their own improvement. Don't know if it's the engine limitation, resources limitation, or something, but some of the features includes the 3P and 4P, ahegao, built-in blindfold and gag like in PH, and the passerby watchers along with the voicelines. Honestly, the last two alone is enough to make me keep PH around. It's probably because these cost money to record/license if due to contracts the voices from PH can't be reused, which is also probably why ILLUSION abandoned the Darkness mode on Koikatsu.
Still, I will give unlimited credits to ILLUSION for figuring out how saving stuff onto a .png works. It is truly their magnum opus so far.
On an unrelated note though, does anyone know of a scene sharing website other than the 55b55, the official ILLUSION page, kenzato, pixiv, or discord?