I love to tweak appearances, It really helps when I can put sliders back to exactly where they were beforehand by typing in the value that was there before. so if sliders could have x/x next to them and grids could have x.y values next to them, that would be amazing

Like some other games have, an option that makes it so there's no sound from the game when tabbed out would be nice

Perhaps include a stethoscope and/or an ekg machine that lets you hear the subject's heart. Their heart would beat faster relative to their arousal, but it would have a reasonable BPM cap to stop things from glitching out and spiraling upwards. Species specific heart rates would be interesting as well (avian species might have faster heart rates. dragons would be slower, etc) but not necessary. I guess this files under general medical fetish, but cardiophilia is a particular aspect of the fetish that deserves extra attention.

Not hard to draw blood though.

Having one or more customizable holographic test subjects in a holodeck like room with customizable enviroment. They wouldn't get you any bonus specimen for science. Just for you to have fun or test new Toys before using on real test sublects.

It would be good to be able to control interactions using keyboard. Using mouse is disrupting the action. Or some other way to be able to simultaneously control the sexual activity and to give orders, comment on interactions etc.

The ability to add different or more ears to your character 

I wanted to ask at you, button "refresh" is necessary, in order to change customers or experimental.

Braces fetish is really underated in furry art, the braces gives the girls (and also some boys) a sexier look, and being capable to cum on some character's braces will make your game really inovating, and also you'll atrack more people