To be frank I don't see any reason changing of this, if a topic can't be on the main board, politics and society,  obviously they will need to be on the off topic board. Even the off topic board in main forum is in similar manner.

Currently the LB and its chill boards are okay like this, the only one that may be needed might be service board, but now I haven't seen much thread about rendering services here again, so I think this may be added later on, except others may want it now?.