Coral additions will rarely if ever add to the bioload so in that regard it's not really a concern as to ho
many you add at once. Since you've just added a new fish (not QT
'd I'm guessing) you should wait a few weeks before adding anything else.
Each time a waste producing load is added to the tank, you should give the biofilter several weeks to "catch up" before adding anything new. Even if it does not add to the bioload. You want to be sure the water specs are stable and it's safe to add them.