What Jack mentions is correct and in newer install there should be enough capacity in the feed wiring and protection.
But there are lots and I mean lots of older CG with wiring installed over the past 30-40 years. Some good some not so good.
Some are also fed with a dedicated line rated for the load 50 amp each leg from a main sub panel each site having a CB in the sub rated near the 50 amp if you start drawing heavy on both 50 amp legs then the 30 too which shares one of the 50 legs it could trip the feed or over time cause damage Did they size the Neutral to cover a mis balanced load ?
The problem is when people start using the pedestals like this without being aware of the layout and not requesting permission it can be a problem.
Now this Teton guy may well enquirer before he connects as others doing this. That’s good. But if not. Well.
Just my 2 cents. Not trying to flame anyone here at all