The DSP field enables that capability. Any track which has a value in the DSP field which matches a predefined "DSP Preset" will use that DSP Preset for playback.
The downside, which I think still exists, is that this functionality will change the DSP settings to the Preset for the track, but won't switch the DSP settings back to a default, or what was set before the track. You can get around that by settign all tracks to a default DSP Preset, and only changing that by exception. You can also use a DSP Preset in a Zone, and then using Zoneswitch to switch to the Zone for that track, and back again later. I think that works fine, but I haven't done it.
DSP Presets are created by saving DSP settings using the "Load/Save" function in the bottom right of the DSP dialogue. Set what you want, save it with a name, enter that value into the DSP field for the track. Done, in its simplest form. Then add your default DSP settings Preset to all other tracks for which you don't want to use the special DSP Preset.
A search of the forum for "DSP field" will find a few threads on the topic.