The current A/B toggle is helpful, but limiting when testing and auditioning multiple settings, or alternative parameter tweaks during mixing and sound design.
Please allow users to switch, store, and copy settings across an expanded set of comparison states (e.g., A, B, C, D, E, F).
This multi-slot state switching would make fine-tuning VST parameters faster and remove the need to rely on duplicating channels, external utility plugins or messy preset saving just to compare multiple settings.
I believe this would benefit every single user substantially.