that's a bug which happened in the original version around v0.5 and which concerns code in old scripts.
it was solved later in the following original updates in v0.6/v0.7, but maybe the mod followed on the v0.5 and missed that fix as it didn't concern the recent scripts
I'm aware it's not the strongest part of the game. In v0.7, I already started to try some new stuff compared to before (with Sonja, Astrja & Mathilda) but these were soft measures and in v0.8 it will be quite the strong measures, with new techniques, new animators, new coding, new structure and then I'll make a poll to check the feedback of players on the different techniques. There will be scenes with your suggestion, I did that already at times btw (not often on lewd animations, though), so I technically know how to do it. It's just that to me, it was making the scene too short and too hypnotical when the loops are repeating forever, and I don't find it very comfortable to read while something is moving behind, so it was not really my favorite technique. I made a poll on patreon on the matter, and it seems like 70% agree with you, so I'll give it a try. v0.8 will quite the lewd laboratory... but it's for science, lol.
Just be aware that spending more time on lewd scenes means that the story doesn't progress much on the other side (can't have everything sadly, and story, looks and atmosphere have always been the most important aspect to me, and I'm not looking to make SnowStorm even slower than it is already). Increase of quality = increase of time. That's the AVN law. I was much faster at releasing SandStorm updates because I used to give very little care to details compared to now. And now, I can't accept anymore to provide bad art, or random stuff.
That said, with experience and maybe some dedicated staff, I'm pretty positive that I'll catch up on the lewd part sooner or later. At first, my art was pretty poor (remember first updates of SandStorm), and now it's one of the strong points. Same can be said on the writing, which was considered weak in SandStorm, and I don't believe it's the case anymore in SnowStorm (can't thank enough the proofing team xD), so there is always hope. If lewd scenes are now getting in the front line of criticisms, it means the rest got better for this aspect to become the new weak point, and thus my new priority and range of improvements.
Also I won't release the 3rd episode before I've leveled up all the aspects of AVN to the same height. DustStorm has to climb another step compared to SnowStorm in terms of quality and technique, like the clear step that happened between SnowStorm and SandStorm. I'm quite ambitious and competitive, so I'm always motivated to do better, and also to do stuff that are uncommon (and thus challenging) in the AVN market.