Most of the ones you show seem to be based on the design of the old industry standard Wico Pin dolly. One thing I can mention about the old Wico dollies (which might have been McCune's issue) was that it came with a special height caster. If you replaced them with standard casters, the height was just a bit too high to fit under some games. It also seemed that at some point, Solid State games got a tad lower in the front. So, you had to tip the dolly up a bit to slide it under the front edge. You also had to be really careful pulling it out so as not to damage the fronts of your SS games. Hopefully, any contemporary re-designs of it take this all into account.

However, I used a lot of what appeared to be cheaper copy-cat dollies over the years moving games around at auctions and Shows and many of them do not have the same ease of lift (leverage to weight) as the old Wico Dollies did.

While I own a Wico dolly, I use Pinskate in my home to move games out of the lineup to disassemble them. They are so much lighter and easier to store. But they are certainly not a good choice for bringing an assembled game a long way over an unsmooth floor.