I strongly recommend caution when thinking about substituting a nut plate for a regular nut. Not because a regular nut is necessarily stronger than a nutplate, but because the bolt likely needs to be sized differently (at the very least installed with a lot more care).
Except for a few cases, bolts are loaded primarily in shear in an RV structure. The best shear strength is attained by having the fastened structure bare its shear load against the full diam. of the bolt shank.
If you look closely at an AN bolt, the shank has has a slightly radiused area as it transitions from the load baring shank into the threaded portion. When we select bolt lengths on highly (shear) loaded fasteners, it is standard practice to to use a bolt length that will have this radiused area protrude beyond the structure so that the structure shear load is baring only on teh full diam. portion of the bolt, and then use washers as needed so that the nut doesn't shank out (run out of threads) when it is fully torqued. This is part of the reason for the "at least one but no more than three threads showing" rule of thumb. Following that rule of thumb will help assure that you are not using a bolt that is too short (has full shank penetration) or too long (risk of shanking out).
If a nut plate is used instead of a regular nut, the bolt sizing task gets more difficult. Nutplates have some un-threaded relief to allow a bolt shank to slightly protrude out of the material being fastened, but it is much more difficult to adjust the bolt length to work properly. The only way is to use washers under the bolt head. If the bolt is overly long the nutplate might shankout and seem to have reached full torque before the full tension load of the bolt is applied to the parts. If the bolt is too short, the parts may not be entirely baring on the full shank diam of the bolt.
So, I am not saying it should not be done. In fact there are some places on RV's it is specified (z brackets for the fuel tanks is one that comes to mind). But that you need to use a lot more care when installing the fasteners. When done in situations that the material being fastened is thick, it is a lot less critical because there is a lot of baring area on the bolt.
I personally wouldn't recommend using nutplates in either of the locations mentioned in this thread. If nothing else, because there is little benefit. Both locations are not difficult to access.... I have done it many many times with no helper. In most instances, these bolts will be a one time installation at final assembly and will probably never be removed.