Not as it stands. It does allow you to specify an ‘Ignore Actor’ list, so the best solution would be to create an array of actors based on the tag list and then store this to pass to the spawn pin.
You can specify the material as for each splat and a flag to flip it vertically or horizontally. Beyond that, you could pass in parameters to the material to rotate the UVs
Not sure of the issue you mean? If you mean the smeared lines on CyberDev’s picture, the Decal volume is too large in one of the dimensions.