Do you think it’s hard to read in the full size image? or just in the mini image? it will likely be an animation when it’s said and done (SD Widescreen), so it shouldn’t be the small image that the thumbnail is.
In 3D Studio Max 4 (the really old version), they used to have a matte material that would only receive reflections or shadows. Whatever was not a shadow or a reflection could be considered transparent. I went looking for this option in Blender. 3D Studio Max had the feature 9 years ago, so I thought for sure Blender would have it in it’s current incarnation. Were you ever able to find the answer to your post? I believe we are looking for the same thing.