I think that the techniques should be learned and not have them directly, I would say that you should start with the basics, kisses, penetration and touch. And then you can use stores outside the store to buy erotic manuals, I think that would play more with the research points.

The last build on Itch.io was back in September, which is now 2 updates ago.

With a widescreen monitor (2560 x 1080), full screen views get chopped at the top and bottom, obscuring information and UI.

I can choose another resolution like 1600 x 1024, but there is no pillar-boxing - it only works in windowed mode.

overall, I love the game but it needs to scale with screen resolution to A: Keep the ideal aspect ratio, and B: Ensure that everything that is supposed to be displayed is visible on-screen, not chopped off.

The 6 tanks currently in "the pit" (currently used to display the subject in the subject selection screen) look nice IMO, and thus I would like to be able to build more of them.

However, since including the playerbuilt ones in the subject selection screen would likely be janky (at least in terms of camera motions when cycling through them), I propose the playerbuilt ones will serve a different purpose:

Storing subjects the player has favorited.

When the player chooses to end the session with a (newly) favorited subject, allow the player to chose which empty tank the subject should be stored in, or if the subject can go home to be called later.(the subject will also just go home to be called later if they are a client or volunteer who does not want to be stored on-site[e.g. because the player did not satisfy them], and research-subjects might want to be paid an additional sum to be stored on-site)

Filled tanks can be interacted with similar to the crafting machines currently in the game, except it brings up that subject selection screen, but only focused on that specific tank and the subject in it.

Could also be used to have certain subjects there purely as "eye candy", like a living sculpture gallery.

The detachment of appendages, which can range from the the small (hand, genitals, etc.) to the big (entire lower body, head, etc.), without, and I repeat, without killing or harming the subject or yourself. No blood, no gore, the goal of this is not harm. 

I have absolutely zero idea if this is even possible in the programming of the game, but if it is, I would imagine an item like a 'detachment band' being used to wrap around certain parts of the subject's body, or your body, to detach them.

How about a Hallway where some of the subjects get exposed to various bondage devices?
maybe with the "prize" and "punishment" button for the audience fun!

The nostalgic sounds of the BGM "Force" made me think of a more pleasant place than in downtown in a deep underground Factility with bigger centre of the lab storation of the clients / clones 

such as these examples shows my imagination:
(these are google images i just found which fits to my idea)