We are sometimes asked to implement a "Track Freeze" feature in Mixbus, which freezes all processors (plugins) and instruments.
Mixbus has 2 very important features:
1) the mixer strip controls (eq, compressor, bus sends) are always "live" in the mixing engine. They cannot be removed like a regular plugin. This allows you to mix like a real console. This means that we cannot freeze the EQ, compressor, bus sends, or fader in the signal flow.
2) Mixbus allows you to move the signal flow order, as part of the mixing process. For example, you can move the fader to the "top" of the signal flow, before the EQ and compressor. Or even before a virtual instrument (in this case, the fader scales the velocity of the notes that are sent to the instrument)
These are 2 wonderful features that other DAWs do not have.
However, it makes it difficult to add a "freeze" feature. Freezing the track's eq or compressor would prevent the mixer from working in hand-on, realtime way that makes Mixbus special.
As a workaround, you can use the Export dialog to export a track, and enable the checkbox to 're-import to a new track'. This results in a flattened audio track, and you can now disable the original track and instrument.