Jusging from the picture, if you glue it at the top, first you would have about 1mm less travel, and second the keys won't register at all because the plastic contact is still pushing the leaf in that position.
And noticed that the equivalent of the brown switch is to glue the white section at the bottom rather than at the top.
I think that you are on to something here, but that you are wrong in your conclusion.
So far we have only theories. I would like to hear from someone who has actually done it. I have not dared mod any of the blue switches in my keyboard.
Here is a picture borrowed from another thread:
You see that the slope after the bump is longer on the white section/blue switch.
In an unmodified blue switch the leaf
pushes the white part down to the bottom*, which means that it does not matter that much that the slope is longer.
If the white part is glued somewhere, then the main spring will counteract the leaf and the longer slope is more significant.
I think that if you glue the white section to the top, then the tactile point will be the same but the actuation point will be lower because the slope is longer.
If you glued the white slider to the bottom then the tactile point would be higher up with the actuation point only a little bit lower -- the same as the reset point on an unmodified blue switch. Either way, the switch would be less tactile than an unmodified blue switch.
*: The force of the leaf is what creates the click. Not gravity alone. You can confirm this by holding your keyboard upside down and press a key. It still clicks with gravity pushing in the opposite direction.
I did a small experiment. I opened a brown switch, removed the spring, held it 90° sideways (thus nullifying gravity) and pressed the slider slowly. After the actuation point, the leaf pushed the entire brown slider to the bottom and there was a click!
