[Too Many Projects]

That set up would be handy with the cameras attached to magnetic mounts.

And you are correct in saying they will only show what you are going to run into, you'll still have to practice which way to turn the wheel and when.

As a semi owner/driver for over 40 years, I can say, practicing is the best way to train your brain to work in reverse.
I once hired a driver with NO experience and paid him 3 hours wages to drive backward around the yard and buildings were I parked the trucks with a 28 ft end dump trailer. He got fairly good at it and better with time on the job.

You have a good sized lot at your shop. Get a half dozen cones and set up a spot where you need to back the trailer into, straight at first and I don't mean backing up 20 ft. Once you can back it up 100 ft in a straight line, with minimal corrections of the steering, and using ONLY the mirrors, then start working on turning it into an angled spot.

The 2 most common mistakes people make are over correcting and turning too soon, or late. Once you have to turn the steering more than 1/2 turn to correct, it's better to pull ahead and start over. Get used to making very small corrections before you're out of control.

And turning to angle a trailer requires visualizing where the axle(s) on the trailer is, not the back of the trailer. The axle is the pivot point of where/when the trailer is going to start rotating for a turn.
I don't mean to preach, but anyone can do this. I don't mean to say it is easy to learn, but, like most everything else, if you want to get proficient, you need to practice and learn. Don't give in to impatience and frustration. Gain confidence by getting good.