As in title - how do I freeze an audio track, which has a MIDI-controlled effect? Freezing it normally causes the effect to ignore the MIDI inputs.
Use bounce to track(s) then archive the original tracks.
This does the same thing as freeze except writes the data to a new track.
When using bounce+archive on a soft synth make sure to disconnect the soft synth using the synth rack. This will free up the rest of the resources used by the synth, just like freeze.