Several moons ago, I used one of these furniture movers as a mobile stand for my Honda generator. It worked quite well……for a while. When I went to move it, the most awful bumping and banging started as I rolled the rig across the floor. At first I thought something had stuck to the castor wheels. No, they’re clean. Then I thought it was a flat spot on the circumference of the castor. No, removal and testing showed them to still be round.
After careful research, aided by several frosty glasses of adult beverage while scratching my head, I discovered the problem. The little castors weren’t designed to hold weight for long periods of time. The inner axle of each castor had, with a hot garage and some time, managed to create an indention where it rested in the plastic wheel! There was no way to repair with for less cost than a new castor so I bought some with inner bearings and problem solved!
I think your idea is grand and will work great. Just be prepared to have a bumpy ride one day or pick up some better castors.
Roll On!