That's different.
The grass detail density I mentioned is a new setting in newer Unity versions (and actually very important). You're talking about the global density scaling factor. It reduces grass density usually to improve performance on lower end machines.
I'm talking about a new setting Unity added to the grass textures themselves.
It's a separate value for each grass layer/texture, so it has to go on the grass output node It goes above 1, which is necessary to make really dense grass (global grass density doesn't change anything above 1) The "Affected by Density Scale" determines whether the grass layer ignores the global grass density (the one you're talking about that's already in MM) It is false by default, which means that if people use MM with a new Unity version, your grass density setting is broken. It doesn't do anything.