As a Roblox developer, it is currently too hard to make a GUI element take up all of the free space of another GUI element on both axes while keeping aspect ratio.
CoverMinSize would be the opposite of ScaleWithParentSize. It would cause the GUI to scale bigger than the size on one axis in order to be the exact size on the other axis.
ScaleWithParentSize:
The frame stays within its boundaries at all times. The DominantAxis doesn’t matter.
CoverMinSize:
The frame covers its boundaries at all times. The DominantAxis doesn’t matter.
If Roblox is able to address this issue, it would make designing GUIs easier, especially when various resolutions and image backgrounds are involved.
FitWithinMaxSize will do this for the DominantAxis. Currently, choosing the DominantAxis doesn’t work and will only produce the left-side CoverMinSize example. Unlike FitWithinMaxSize, CoverMinSize would disregard the DominantAxis entirely and always cover the space on both axes, as the above example shows.