Suggestion: make it easier to swap positions with another player. I'm not exactly sure what this would look like.
But something that makes it easy for 2 players to swap positions, if they both agree, without either one needing to move to observer or empty slot, and without the host needing to manually swap them.
Let's say I'm playing with Jip and I want to switch slots with him. I right-click on his name, choose an option called "ask to switch," then he would have an option appear in his lobby, if he right-clicks on my name at that point, instead of "ask to switch," he would see an option that says "switch" and if he chooses that option, we swap positions.
So we would need: (1) a way to offer to switch with another person (2) the fact that we chose it would need to be communicated to the other player in a way that doesn't spam/annoy them and (3) the other player would need the ability to accept an offer (4) everybody else in the lobby would also need to be updated that the switch happened so everybody in the lobby shows everyone in the correct slots . . .