For instance it could have a separate cover just for closing the lid. Like mechanical keyboards do but this one would be for closing.
It could be 3d-printed or something.
This one is for keyboard itself but I expect it to cover all of the bottom chassis so that the pressure would be dispersed to the frame of the closed screen:
Like this (this is really sloppy sketch but I don’t care):
That looks ever so comfy to type on. Sorry, couldn’t resist. 
Might I suggest you attach it to the bezel instead.
Not attach it permanently.
You’d open the laptop and remove it. So you’d be carrying the laptop with it but open the laptop and remove this green part.
Maybe it could work idk.
Also it could be attached to bezel. It would work the same.
All good and well, but I still feel it a missed opportunity not to accommodate discrete laptop switches from the get-go.
As you say, altering the lid with a deep bezel to recess the screen may do the trick. The frustrating thing is this only needs to be very few mm from the standard design, you are going to the trouble of commissioning an aftermarket part for something that should have been standard.
Probably a dumb idea, but with enough screen protection (e.g. with a keyboard cover as mentioned here: Input Module Keyboard Switches - #21 by Martynas), could the hinge’s force allow the laptop to be closed while depressing Cherry ULP keys (3.5 mm tall, up to 1.8 mm travel)?
The actuation curve of the switch (MX ULP TACTILE - MX ULTRA LOW PROFILE - MX SWITCHES - CherryMX) suggests that at 1.5 mm depression, the force per key is 30 cN, so even with 50 keys, the total force would be 15 N. I have no idea what the hinge’s force is as a function of angle, or even what the right order of magnitude is there. Could that be altered by e.g. magnetic strips on the keyboard edge that attract the bezels to shut the laptop stronger?
Do laptops have to close, anyway? 
Ideally, the single-key PCBs mentioned by @nrp would be great, but if those don’t work out, it would be nice to be able to use off-the-shelf parts to make a split-ish ortho input module.
What I would love would be something that would adapt a T-class Thinkpad keyboard and track pad to the framework 16.
Given that they are plentiful and inexpensive in the aftermarket this doesn’t seem entirely impossible. Might have to do a bit of soldering to replace the existing flex cables with a new design that handles the signaling and connects to the right place, and I haven’t measured whether there is enough space, but I can dream.
I wonder if any of the aftermarket clone vendors would do a run of a thinkpad-inspired keyboard and track pad for the 16?
A bunch of people are working on thinkpad-based keyboards over in Thinkpad keyboard mod (super early stages)! – some of the discussion has touched on the feasibility of expanding the hinges somewhat to allow space for slightly larger keyboards.
