It sounds like you are talking about the hidden ‘Displays Drive Canvas Rendering’ setting – when this is turned off, you can specify the FPS for each individual layer or group.
However, this doesn’t cover Vuo / QC based plugins. Offhand I’m not sure how feasible it would be for us to add this, as we try to keep data-sources and rendering in sync, but this is a noteworthy use case so I’ll put it on our to do list to see if this would be possible.
(Please feel free to email us a copy of your Vuo plugin and a VDMX project file for us to use for testing! Always useful for us to have real world cases so we know what we are dealing with.)
In the meantime, your best bet might be to try to find a way to throttle from within the Vuo composition itself, skipping the work it is doing if it is still computing.
PS. If you are looking for that hidden setting, in the Rendering preferences, if you scroll to the bottom, there is a place to access the advanced rendering prefs. We strongly recommend against using these, as they are for our own experimenting with different types of rendering methods… so they are definitely use at your own risk, and if anything weird happens, try restoring to the default settings immediately!