Following is what I found from testing in Wavelab a while back. The function to suspend VST3 is probably not very effective if you use 3rd party plugins with the Steinberg programs, because very few of the plugin makers support it. Suspend VST3 plug-in processing - Cubase - Steinberg Forums

"
In Wavelab, these VST3 plugins suspend processing when no signal present:
Steinberg
Stillwell
Eiosis

These don’t:
Voxengo
Sonnox
Izotope
Waves
A.O.M.
DMG
Slate
Kazrog

I don’t know if this covers all plugins made by these plugin makers, but that’s what I found testing one plugin from each in Wavelab. So it’s certainly not a comprehensive test.
"

I think the suspend function is possibly more effective with 3rd party plugins in Logic and ProTools (not just VST3), not the Steinberg programs.
Logic disables plugins when there is no active region - JUCE . Thats just what I’ve heard though, don’t know it from fact or experience.