I just thought about something. So okay, the server has a limit on 15 dynamic objects. Because we don't want to communicate too much over the network. How about that:

The client and the server would have the entire scene running. So all of the objects are present at all times. But over the network, there are only the 15 closest ones that are communicated.

So say I'm in a building somewhere on the Moria's Race City Arena, I see a bunch of shelves. Only those close to me are sent back to the server, while I see all of them.

The server also sees all of them. But he know where I am, so he sends only the 15 closest to me. The others have little to no effect on me, so I calculate them myself, based on the positions of the players.

Just a shower thought.