Currently, you're stuck choosing default patterns and decals for your characters.
While custom patterns/decals are probably going to be in the final game, I have a related idea.

In an editor similar to the decal adder, you could 'paint' a color onto your character, with various brush and erase tools. The result would be a custom layer, fine-tuned to your character settings.

Im not a diaper fetish person for the baby aspect, but for the cuteness and humiliation factor, I get it doesn't tickle everyone fancy but its just what my fetish is, but it could also just be a peice of atterire

The ability to attach a device to your subjects that lets you control their bodies while they're conscious, allowing you to make them say and do things involuntarily such as masturbate or have sex, but with visible intention to resist.

I think it's good idea.

If Electric masturbator(For Example CycloneX10 etc...) works as Character's orgasms Player can Experience sessions on Rack Laboratory more realistically.

The ability to change a subjets gender thru perhaps potions or vials, perhaps because you like to try it out on the subjet? or perhaps they came to get the gender changed? As well as bimbofying them to start to get abit less brain activity if you woulc continue to have your way with them for quite a while. Maybe if made into possible to turn off and on the feture.

Currently, Sensexa causes the subject to feel pleasure, and Nul-Sensexa causes the subject to feel pain.

Instead, have Nul-Sensexa make it harder for the subject to feel pleasure[and nullify the effects of any Sensexa in their body], and make an additional chemical/nul-chemical pair for causing/inhibiting pain.

Use case: You accidentally overdosed your subject on Sensexa, and wish to nullify the excess. However, currently the only way to do so is to use Nulriset, which will also nullify any other chemicals in their body, which you might not want.

Feed test subjects to make their bellies grow.