FCCS MR: Is there a way to disable or lock the Grid POV ellipsis to prevent invalid POV selections?

I am working on a Management Report in FCCS that uses a Global POV and two grids, each with its own Grid POV containing specific hardcoded members except the Movement dimension. Users can click the ellipsis (…) in the Grid POV and change the member selection, but when they do so and click OK, they receive the error:

Grid2" has an invalid intersection on the POV dimensions. Select a valid combination of POV dimensions.

 

Is there any supported method to disable or lock the ellipsis in the Grid POV so users cannot modify the POV at the grid level? Alternatively, is there a configuration that forces the Grid POV to remain fixed while still allowing the Global POV to be editable?