I had all of my truss rod covers off for years.
Then all the sudden about three months ago I was adjusting the truss rod on one of the new guitars I just bought, and I put the cover back on.
I though, wow that looks a lot better without all that wood showing.
So I decided to get all my parts organized in a little plastic organizer for nuts and bolts or whatever.
I couldn't believe how many parts for Ibanez guitars I have laying around.
I have a whole Ziploc bag full of colored knobs and pickup covers.
All kinds of trem parts.
There are like six 5 way switches and half a dozen pots, etc.
I have all these plastic cases for Dimarzio pickups.
There is a bunch of case candy and back plate covers.
I realized I had not adjusted any of the necks in so long that I should just put the covers back on.
So, I started putting truss rod covers back on guitars.
I think after so many years of being in a stable environment with the same brand and gauge for strings on them, they just don't move at all.
I had a pile of the truss rod cover to sort out.
Some of them had different hole patters, just a bit.
I had one I could not find the guitar for, I just found it two days ago, my RG7620.
I put the back plate cover back on too.
The thing is so mint I had too.