Yup, when I drove fire apparatus we didn't have backup cameras so we always relied on the mirrors and is why all of my cars now have add-on 2" convex mirrors. Once I trained the kids to use the convex mirrors they love them. It's actually difficult for me to drive a rental car without convex mirrors.
And of course, when backing fire apparatus you ALWAYS have a spotter watching the rear and minimize backing as much as possible, which is my plan for the RV as well.
The side cameras would be ("should be") nice as a pseudo blind spot detector so I may have to fiddle with the output from the cameras once my GT5 34H5 arrives to see if more or less amplification would help. If the display washout is angle-related it may be a low output issue from the camera. I suspect that FR is using the Jensen Voyager cameras like this one:
https://www.asaelectronics.com/left-...n-cameras.html
Ray