When using Layers/Multiview, have an option on the Position tab to lock a given layer in its current position (i.e., lock the values for PanX and PanY), creating a window that permits panning and zooming to still take place but only within the window. In essence, panning left or right would automatically adjust CropX1 and CropX2 by the amount panned, panning up or down would automatically adjust CropY1 and CropY2 by the panned amount, and zooming would automatically adjust all four crop values by the zoomed amount.

Use case: I have talent cropped in a layer. The talent has moved slightly to the left and I need to re-center him. Without this feature, I need to adjust PanX, then compensate by adjusting CropX1 and CropX2 commensurately. I would never attempt this during a live shot. With the feature, I would lock the layer then adjust PanX. That's it. I would even do it during a live shot.

+1

I think (if I understand the issue right) we have discussed this a few times over the years. Search for "Multiview Zoom", a couple of pointers:
https://forums.vmix.com/...not-increase-when-zoomed
https://forums.vmix.com/...ltiViews-with-MultiViews