Hi, my I've got two separate streams going with two instances of RadioBoss.
Is there a way to have them both go through a singular instance of Stereo Tool?
Stereo Tool can only process two channels at a time (one stream) per instance, and one instance per license if used to broadcast. Stereo Tool Enterprise can do multiple instances in one stand-alone application, but each one needs its own license. You can combine both inputs, process them as one stream in one ST instance, and then output the mix to both RadioBoss instances... but that's probably not
what you want.
You can try to pre-process your music if stored locally using Thimeo Watchcat, which you would use your ST license for. You shouldn't need a Watchcat license unless you need to process audio from video or script a special codec/type to render to.
Otherwise, you need to use a second ST license for a second simultaneous stream of different content, even if you want them processed similarly.