@benjamin @kajer @mikesiegel I've seen folks swear by some of the alternatives as well, though I haven't actually used any of them myself, tbh.
https://patchbox.com/dev-mount-cage-nut/
https://www.rackstuds.com/
@benjamin
i do not see the point of the video that's just a slideshow.
The GIF further down the page is much more useful.
@kajer @mikesiegel
(haven't tried these but heard they're much better than cage nuts)
@wolf480pl @mikesiegel I've used patchbox's similar version (/dev/mount). While they do work nice, the issue you tend to have with them with is rails tend to be of fixed length, and often don't have enough space to pull an inch+ longer than designed, so you can never get the rails on the post properly.
At least with the patchbox version, the bolt is welded onto the bracket. If you accidentally turn too hard, you can shear the weld and you just end up with a spinning bolt you cannot get out.
@wolf480pl @mikesiegel Dell's ReadyRails are nice, used those plenty. Even so, there is a limit to how adjustable they are, same for most rail kits. Even more impactful when you have deeper racks.
I had to mount an older Citrix SDX. The rails could extend to about 30.5", mounting in a 29" deep rack. With the /dev/null devices had to fight to get the end of the rails around the bolts.
Don't get me wrong, they're very cool just some caveats. I have the rack studs in a shopping list to try, too.
@mikesiegel I maintain a cloud, these are still required.
They just outsourced the pain. 
@mikesiegel Over the years, I got three of the shaped sheet spring steel things. I have not done this job for ten years. I still have them in my cellar, know precisely where they are, and will never lend or give them away.
Because, fingers.
Was your employer to cheap to get you one of this?
@mikesiegel
You can move back: https://www.rackstuds.com/
These cage nut tool https://www.amazon.de/-/en/kwmobile-Pliers-Cage-Nuts-Size/dp/B07ZJB7HCX are pliers that look like an oversised nail clipper, and works in a very similar way.
@mikesiegel I switched to Rack Studs: