I think it'd be a cool idea to customize the gender identity to transgender, nonbinary, agender, or cisgender. Adds a little more fun for the queer players haha..

Something I thought that would spice things up, how about some gemstone/crysalline embellishments? Could be good for those people who like giving their character the crystalline treatment

Here are some shapes:

And here is how you could have them colored in game:

When you edit the lab, sometimes you want to put something against a wall as closely as possible, but have to constantly go back and forth until the object is finally against the wall. There can be a button that automatically props something against the wall in the mode before you click again to finalize the placement of the object, so basically the player can move the object left and right, but the object is to the wall at all times.

Also sometimes you want to align an object with another object, but you have to continuously place and remove it again and again like an OCD freak in order to place the object in virtual alignment to another object. For example, I always had trouble with ceiling lights- I wanted them to be linearly aligned with one another and not askew or off-alignment or something like that. This can also be the same for rack chairs or tables: some people don't mind one being somewhat more forward than the other, others do mind though. There should be a button for automatic alignment: place one object somewhere in a lab room, and then when placing another object, you can press the button to either make the second object automatically align with the first, or have a visible line on the floor where you can move the second object alongside the immovable first object, so the line rotates around the locked first object with the movement of the second object, and then you can place the second object at an alignment with the help of that visible line (whether you make that line perpendicular to a wall or 45 degrees to the wall or something). If you have a third object that you want to align with straight with the first and second objects, with the automatic alignment button, you can toggle the first two objects and automatically place the third object right before or after or in between the first or second objects, or use that line on the floor or ceiling as an alignment guide to help you place the third object somewhere with respect to another object.

I'm suggesting this for the more science type people like me. I was thinking for species like reptiles, birds, or any other species that would have a cloaca, have the editing option to remove the balls of males and make the penis internal until arousal.

I really do like the songs in the game, but I think an additional 1-3 songs may add just enough variety so that there is a good amount of music playing in loop in Rack 2.

Add braces as an accesory for any subject that has teeth

Some of the racks are designed in such a way that they bind hands and ankles only while not having the subject completely stretched out, leaving some wiggle room for their crotch. For instance, the standard rack and stocks are a good example of what I have in mind, the table and the inverter — not so much. Somewhat similarly, none of the equipment we have seen so far constraints movement of one’s head. Each piece of equipment allows various degree of freedom for different body parts of the test subject, and therefore some interactions can be enacted by them rather than by the player character.

What if there was a mode for the PC to remain more or less static, with the subject in the rack controlling the depth and the rhythm of interaction instead? I was thinking of a completely automatic mode, where subjects themselves decide on intensity of their experience according to their preferences, friendliness, empathy and dominance. This mode may be accompanied by a second display, that would show the locked-up subject your stats you have already unlocked — like arousal, anticipation, strength of stimulation and exhaustion — just like the monitor you have for them.

This could be a rather good tool for adding a layer of will to subjects, making them feel more alive.

Partners with high empathy may suggest pleasing you of their own volition, and adjust their speed according to the stats they see on the screen so as to make it feel good for you as much as possible (maybe the emotional high is just as important to them as physical stimulation, or even more so). Subjects who like overstimulation can help themselves to be as rough with you post-orgasm as they would like to be. Dominant ones may try to order you to stop and let them handle things their way, submissive ones may obey your order to show you what they are worth. Any subject might get a dopamine burst if they stumble upon one of your fetishes themselves and it corresponds to theirs, or they simply do not mind or are friendly enough to tolerate it. Et cetera, et cetera.

P. S. Depending on how far you want to take this suggestion, if take it anywhere at all, you could also turn this into a kind of a minigame, where you let your partner move and try to sync your own motion with theirs. How to do that, though, is a different matter entirely and I have a little to no idea of how exactly that could work beyond the very rough idea above.

Would the layout of the lab work better if instead of going into the tower, down and /back/ behind you out, to turn the lab portion of it around so you can go into the tower, go down the elevator and without turning around, right out to meet the clients. 

I think it makes for a quicker transition in between soliciting clients and right to playing with them... something I picked up from level design in other video games.

And personal perception... I always thought having to turn around to meet the clients was a little off, it toyed with my habit of going from the secretary right to the client. I've even looked at jumping the rails to get to the lab a bit quicker if one of the clients looked really hot.

Odd subject, but some would enjoy seeing A character pinning the character on the table down under their weight as a form of domination. Like sitting on/laying on/stepping on. 

The laying could double as a form of cuddling! :D

Allow the user to have a bit more filtering options such as specific genders, genital types, etc