Add each link as an OBS browser source at the size shown. Each always shows its own projector view. Native canvas 2200 × 1054; any size with the same shape works. Uses the live comp; add ?comp=<id> to pick one.
https://blockbountytest.com/stream/livehttps://blockbountytest.com/stream/overviewhttps://blockbountytest.com/stream/resulthttps://blockbountytest.com/stream/standbyhttps://blockbountytest.com/stream/join