So I am about to install this nut. Notice the sloped gap on each side on the bottom.

It's slightly too wide so i will have to sand the side down a tiny bit. That's not a problem. But I'm quite bugged by those air gap on the bottom since my neck slot is flat. Is it a good idea to fill them with something like plastic or white glue? Just to make the full contact with the neck slot.

ESP Standard Eclipse I CTM VW
ESP LTD Deluxe H-1001
ESP LTD Deluxe Viper-1000 STBC
ESP Edwards E-EX-100STD
Warmoth Paulcaster "Tiger"
Tanglewood TW170 AS
Vox Tonelab ST
Blackstar HT-1R

if its too wide, then be careful that the string spacing isnt too wide. otherwise your strings will sit next to the fretboard edge!

as far as filling with glue, many glues like wood glue shrinks some, especially if its "puddled" or a lot it applied. so it wouldnt fill well in my experience.

hopefully someone else has a better idea...