We're slowly adding most of them back in! The plan is to add customization options through R&D rewards or exploration loot, to give them a story purpose and show Asterion's reaction to getting each of them. For example, the bell asset had been sitting in the game files for a while, but we decided to make a dedicated scene for it that explains it's a memento of a previous master Asterion remembers fondly. We plan on doing that for most of the assets.
Some of them won't make the cut, though. A lot of these assets were made on October 2019, between the first and second builds (the first build cuts off right after the fireplace scene where the player chooses Kota or Luke), and we were basing the story off an original draft that took itself less seriously and had Minoanon roll with random ideas from very horny anons. So there are suggestions like torn handcuffs that don't really gel with the current tone that I don't think we'll end up using.
As for nipple customization options, Asterion is just not ready for that. Yet.
The highland bangs are definitely going in, everyone on the dev team fucking loves them (though I'm not happy with the current asset, I'll have to redraw it). We haven't implemented it yet because we were waiting for Oscar to join the hotel as proper staff, so the player character can get the idea from him. A kilt would look rad, too.
As for headwear like hats or paper crowns... we have one small complication, which is that Asterion's horns will be customized too, so the horns would have to be split into a front and back layer to put a hat in the middle. Same for the horn accessory layer. I'd say it's a little tedious but might be worth doing in the long run. I could try it.