Yes, I tried adding beyond 100. The problem is that for looking up, the best eyes-closed value might be 113, for looking straight 100, and for looking down 93 or so. So the problem is that it varies with eye angle, not that it's limited to 100. Maybe Reallusion can come up with a solution like you suggest, based on joints or so, or a controller that takes eye angle into account when blinking. What would be important is to tell us how the controller works, so we can recreate it in the game engines we export to, or they might even provide some Unity scripts.
You did adjust the morph when blinking to add extra? Try to make the eye look up, close the eyelid, add extra numeral value to 100 until it closes. You will know if you reset the eye if there is any additional morph influence to the eyelid making it not completely close. Even in the Face key editor, you can make the lids go beyond 100, I think in the Face Puppet tool as well with expressiveness. Personally I think the eyelids may do better if they had their own dedicated joint and centered exactly where the eye joint is and then is rotated to close with proportion, I've done this on a custom character where the eyeball bulges out round from the surface, something like this needs to pull the eyelid closed as a spherical rotation with a morph, morphs alone only work like like a height map basically only morphing in one direction. A workaround would be to make custom morphs with the direction of the eyes together with the eyelids closed with the extra value to close it -dreaming Eye Morphs
Unfortunately, none of this solves the issue. If I modify the blendshape to close more such that the eye closes completely when looking up, the eye closes too much when looking straight, and even more when looking down. Already with the default blendshape, when looking down and blinking, the upper eyelid closes far too much, it overlaps the lower significantly. This is quite apparent in closeups, but maybe a bit less then the not-closing-completely issue when looking up. I don't know whether this problem can be solved at all by modifying blendshapes or meshes, even on Reallusion's side. Maybe having blendshapes that move the eyelids up/down when looking up/down means that any additional blendshape that is supposed to close the eyes has to take into account where the eye is looking to figure out which value to use for "eye closed completely". This means when I export the character and use it in an engine and want to make the character blink dynamically in a game, I have to do calculations based on eye angle to figure out how far to blink. This is quite a bit more complex than what we had before, so the new blendshapes come at a price. If there is no way for Reallusion to provide blendshapes that both move the eyelids up/down with eye look and close them with a blendshape that uses the same close value no matter where the eye looks, then we have to live with that and work around that. But I don't know for sure whether that's the case.
In eye close/blink morph raise it to maximum (100) then make it 122 or less hit update.. if that doesn't look right press undo and try another. You have the full ability to modify the morphs yourself either setting the morph number higher and updating or editing the eye mesh with edit mesh, GoZ etc. Knowing this is standard except adding a number past 100, there are no hints on the screen, maybe not the manual either.