I have a customer that has a house attached to a very large garage on the right. Just to the right front of the garage is a poco pole that feeds across the garage to the house. Looks bad. They want the garage to be a game room / shop. I think this would be ideal for the type of panel here. Move service to corner of the garage and feed the 200 amp panel in the house from the garage.
And to summarize all of the above...
The loads connected to a feeder can't be greater than the feeder's ampacity, and/or exceed the rating of the breaker that protects that feeder. This is based on various sections of the code, including article 315, motor conductor sizing, transformers etc. This is also generally applicable to outlets and equipment as well. For example, it is illegal to plug a typical Greenlee smart bender in to a 15 amp receptacle. (I use this because I have seen it violated more times than I can count).
So, theoretically, you could feed 10 panels using feedthrough lugs, as long as the feeders and equipment didn't exceed the rating of the protecting breaker and the calculated load per the NEC was also less than the rating of the feeders and breakers.
This could seem unlikely, but not so much. Say you had a lab, where they wanted to be able to turn off every receptacle on a table individually and they had 100 table top receptacles. Each one was only expected to carry a small electrical load.