30 amps or 50 amps is just that. The CB will not let you pull more. If I pay for it I am authorized to pull upto that amount.
Let's use an analogy. If you go to a burger stand and order a 1 lb burger, pay for it and they bring you a 3/4 lb burger. Are you happy? No. Well, this is no different. Now if they bring you a 1 lb and you only eat 3/4 of it, that is OK also. You get what you pay for and you can consume upto what you want.
If a CG has low voltage, who is wrong? The camper who pays for 30 amps or the CG not providing what is paid for. To me, it is upto the CG to provide what they charge for. If there is cheating going on, it is the CG that cheats people by expecting them to live with less than offered.
I have been in CG that have brown out situations. I have been in a CG that had a 200 amp CB feeding 8 30 amp circuits.
I have an Hughes autoformer.