A question about sound management for the stage

If one wanted to have a set of sounds ready to be triggered, perhaps from a booth, according to different cues on the stage, anything from short sound fx to full tracks, how is the best way of organsing this? Is there a convention?
I thought about a few ideas, including using Halions function to allocate a (finished, wav) sound to a key - but there are only so many keys.

A complicating factor is I am working in Surround SOund

I need to have the sound play immediately of course, and possibly fade in

There are lots of sounds too many for each to have a mixing channel each.

Is there some kind of legend or bible on this?

Arranger track?