[Mean]

When using Incognito's streamer, you just do the CreateDynamicCP code, and as soon as you do that, players will see it. If you want it for one player, just do TogglePlayerDynamicCP and the checkpoint will immediately show, nothing else you need to do.

Why wouldn't you use SetPlayerCheckpoint? It can be used if you don't need to show multiple checkpoints. Streamer is better IMO, but you can use SetPlayerCheckpoint.

In short: yes, you can use the streamer plugin for mission checkpoints. I don't see why not.