Nice build!
Switch stickers/films: does it make a difference in any aspect of the switch?
Does it feel kind of springy in the middle of the alpha keys, e.g. T, Y, G, H ?
Top-mount seems to be what Korean keyboard designers go for these days. Some other members described top-mount as some nice springiness in the keystroke compared to the tray-mount supported by standoffs in the middle.
I made the gap film to save time.
It takes 1/5 shorter than stickers.
And it makes low-pitched tone when switches pop up.
It is not compulsory part.
Many GHers ignore sounds.
In korea.. We call top, plate, bottom to 3 piece housing.
Plate and tray to 2 piece housing.
Linear user like 3 piece housing.
(I am a linear user.. So I like 3 piece housing and make it)
Tactile user and non plate user like 2 piece housing.
3 piece housing is more expensive.
Use many kinds of kbds, and you will find suitable to yourself.
If you can't find.. Try to make kbd for yourself.