Create and clone block and wheel entitys with no name attribute, and dimensions in %strings
Create a selection of filters for testing
Check that the selected filter applies correctly to the selected entity only
Make sure the filter correctly covers animated entitys (when selected), and no other part of the canvas
Check that when the filter is applied to the group, all entitys (but not the cell) are affected
Check that when the filter is applied to the cell, the entire canvas is affected
Notes
The gray areas when chroma filter is applied at the group level is expected behaviour - all entitys get filtered at the same time, thus when a pixel is removed the underlying color will be the cell's background color
The blur filter is generally much slower than other filters, particularly in Edge. Entitys and groups that need to be blurred will be more efficient if blurred once and the result captured as an image for use in a Picture entity.
Similarly with the matrix filters (though they are a lot faster than blur)