Bed rail cap, T-30 screws

There are five T-30 screws holding the front bed rail cap on (5 yellow arrows in stock photo below), but I can't reach my hand in to catch any nut that would drop off the backside.

I want to add a couple D-rings under a couple of these screws so I have to take the screws completely out. Does anyone know whether the nuts on the backside are somehow held in place, and you can remove and re-install these screws without needing access to the nut on the back?

I'm not removing the rail; just taking a couple of the screws out temporarily, so I can add a d-ring under the screw head.

 

There are threaded bosses on the back side.

 

Thanks for the replies.

 

Now if I could just find some hardware...
These are too small: https://www.homedepot.com/p/OOK-20-...ng-Hangers-with-Screws-3-Pack-50206/100004803
and these are too big:

Audew Cargo Tie-Down Anchors,8PCS 2" Diameter Black Steel V-Ring Bolton Trailer Anchor, Replacement for D-Ring Plastic Flush Mount Pan Fitting Tie Down for Trailers, Trucks and Warehouses

https://www.amazon.com/dp/B07DX1X548/ref=psdc_15737881_t3_B07H9ZKRH6
and I can't seem to locate anything in between (the screw diameter is 15/64, or 5.94 mm). I don't need anything heavy duty.