I would say that it would certainly make it feel more like a mix between horror and lewd if more lewd elements were incorporated into the actual gameplay loops and not just unlockable scenes and such. Don't get me wrong that can certainly work but just in my own experience I tend to enjoy games that do fully blend their themes because the gameplay is going to be the main part that you are going to see so if you don't have one of the main parts of the game genre involved in that more then just loosely tacked on or as purely rewards then it doesn't convey the idea that they are truly a blend of them and instead give the feeling that it is a horror game that just so happens to have attractive characters that you won't be able to get a good look at and some spicy extra content. pretty much it could start to feel like an afterthought. I would also advise against only implementing those elements in the level design because while that will certainly help, being able to interact with both the horror and lewd elements will make it stick in your mind so much more. Think about it, what feels more scary for a horror game? seeing a poster and/or statues of a monster, or actually seeing and having to avoid and even having to deal with that monster or even having it keep reminding you with a good degree of certainty that they are around you, doing things and just keeping that pressure on you. well that's the same kind of thought process that should go into the lewd aspect as well, I have seen most other games do this by having it be part of the gameover screens though you can certainly make it work in many other ways.
With that all said I will say that this is a fun game and I do like what I have played so far, and I really do hope that my advice helps because I really do want to see this game develop lewd FNAF games are honestly such a gem as there really aren't any other lewd games that I have been able to find that tend to be able to blend lewd and fun to play so well as these games along with having a lot of the elements that I personally enjoy.