Replacing a Locking Nut

[GunpointMetal]

So this is obviously an ultra-niche request/question:
I have two Agile Interceptor Pro 930 guitars with the Kahler bridges. I tune super, super low and never use the trem, so they are locked down. I'd like to replace the locking nut with a string retainer/zero fret so I can retune my low (seven string) B string from B to A, allowing me to leave my 8-string at home for gigs. I've also had a few issues getting the nut slot on the bottom string right, and I think a zero fret would make up for this issue, as well. Did some googling and couldn't find anything or anyone making anything. Anyone know of anyone that's done this, or someone who could build something like this?

 

[MaxOfMetal]

If you're having trouble getting the nut just right, installing a fret isn't going to be easier.

There are aftermarket nuts with built-in zero frets, but obviously not for 9 strings.

Any reason why you don't want to leave the locking nut? You don't have to lock it.

 

[GunpointMetal]

If you're having trouble getting the nut just right, installing a fret isn't going to be easier.

There are aftermarket nuts with built-in zero frets, but obviously not for 9 strings.

Any reason why you don't want to leave the locking nut? You don't have to lock it.

I was using it that way for awhile, but I tend to catch my hand/fingers on it, especially when I'm doing those nasty
0
1
0
1
chords on the bottom four strings. I also don't like tuning up/down through that nut repeatedly because it's gonna weaken the string compared to a plastic/bone nut. The hard part of getting the nut right is that since it's metal, and about 3/8" deep, for my lowest string I basically have to file down the thing from front to back and with a .118 gauge string, thats a lot of material to remove. I'd prefer to just pop it off and be able to put it back on if I wanna sell it without it being completely filed to shit.