Still? I haven't bothered playing with this in a while. I was hoping it was changed by now.
So was I. I can't see any real use for how it is now. It should set the DSP for the song to which it refers, and unset it at the conclusion of that song (except, see below).
The other issue, which has been discussed before, is that in the DSP section there are both global and local settings. Global settings affect the zone, not just the song. Those are Output Format, Volume Leveling, Adaptive Volume, Room Correction, headphones and Convolution, and should be excluded completely for per song settings. Everything else would be the Local settings.
Within the Local settings there appears to be only one setting available for each; On or Off. This makes the assumption that once you come up with a setting for each that works with some songs, that it will be sufficient for all songs. I don't think it is or ever could be.
You do have the option within DSP of saving a combination of settings to a name. Once that excludes the Global settings and
includes individual parameters of each DSP that is active it would be very usable. Then all you would have to do is make a template for a song or songs, and switch to it by name in the DSP setting in file flags. By name you could identify if it's a specific setting for an album, or for a specific effect or contour (group of DSPs set a certain way).
I haven't tested all of the DSP options that are saved, but did determine that calling the DSP by the name you saved it as in the DSP section does affect convolution, so right there it's a fail. Since you may be using this playlist in any zone you couldn't use the DSP settings as they are.
Since lookahead is already available for 'next song' DSP, its name could be examined, and if it was the same as the one currently in play, no need to reset the DSP and reselect the same parameter for that song. That would only happen if the next DSP setting was different than current. An next entry with no DSP defined would reset the DSP selection to none. That would be killer!
And lastly, to help debugging DSP settings when needed, update the DSP Studio display in real time to show what goes into effect and when.
Nirvana!
--Bill