I haven't played the previous versions, am I understanding correctly that; this games earlier version was on unity and they moved to renpy or was that about their other older games. And they removed some things like pregnancy with the move?
So, there were three games.
DonTaco feel free to correct anything I get wrong.
BLC - Unity. (Big Long Complex)
SC - Unity. (Small complex, this one).
Taco Verse Tales - Renp'y.
TLDNR:
SC and BLC were unity, BLC moved to Renp'y, SC was merged with Taco Verse Tales into RPG Developer Bakin.
Because new engine, and the fact dev has improved the quality of their scenes, the old content was either not ported or remade. BLC is the one that had pregnancy in the Unity version. (will eventually have it again afaik)
Honestly, I recomend playing the older versions, just to see the difference, was actually jarring how different it was. I did that with SC, and honestly had thought old SC had same quality as current in my memories, I was wrong.
So Dev only have 2 active games being developed, BLC and SC. Once SC is in a place they are happy with, they will go back to updating BLC, and possibly changing the engine again due to request. (no idea if they will move to bakin tho)
Fans quite like the 3d moving around. Myself included.