Each Apollo unit has a finite amount of dsp. You own a quad unit. So eventually you will run out of dsp based on which plug-ins you have active in a project or in console. If you add to your system, say an x8p, that’s a hex. So then you’d be up to 10 cores and that would allow you to use more of the dsp plugins.

I highly recommend going to YouTube and watching as many hours of uad office hours as you can. You’ll learn a lot.

There is also a chart of dsp usage per plug-in on uads website. It will be trial and error for a while but you’ll get it. The new native plugins will be helpful as those don’t need dsp and you’ll be able to balance some plug-in usage between internal Apollo and you computer.