Alright, so you want basically to keep spawning O2's over and over again without having to repeatedly type it..
Not sure why you would want this, would intensely stretch the servers performance quality at the time and unless you are using a weapon that does an insane high amount of damage to keep instantly kill them, eventually the server will crash/freeze.
Why is everybody in this section so needy for useless and weird commands that make zero sense in every possible way.
Only way I even see something like this useful for Coral Gifts maybe if you were hosting a spawning event or something, even with that, you can just type the amount in the actual command execution and it will stack X Coral Gifts on top of each other.
But having them spawn one after another with almost any other entity that has a unique behavior.. uhh.. well.. all I can say is that you're screen will be filled with hundreds of O2's before you can even get the chance to kill a few.
I guess someone (I will when I get some free time, haven't touched private server stuff in weeks, maybe even a few months) could make a command such as "/spawnloop X E"
X = amount of time in MS in-between spawning the next entity
E = entity
and then another command to stop it, or just add it into the existing command (Example: "/spawnloop off").
example of how my command would probably work and a good idea of how anyone else should make it if I don't get to it first..^