Peter Verbeek - 2021-12-19

Unfortunately, that isn't possible. Currently there's no way to see any output on the interface of a VST plugin.

Equalizer APO has a 2 step implementation. The VST plugin interface you see isn't the one that is actually doing the sound change. A second running plugin is doing this. In short, the first creates an Equalizer APO command which is sent to the second one. That's how Equalizer APO works. Its audio changing engine gets commands to change the sound. In this case it gets parameters of a plugin interface with which it starts a second run of the same plugin. Then it puts in these parameters. But this is all done in memory, say the background, without awareness of the user.

As the developer isn't very active on Equalizer APO, I don't expect an update soon on this matter.