My biggest issue with frozen tracks is you cannot add volume automation because if the track is subsequently unfrozen the automation will be lost. So I routinely bounce soft synths to a separate audio track in a separate folder, where it can then be treated like any normal audio track. I'll typically freeze the synth and then CTL-drag the frozen audio into a new track, archive and hide the original.
Now you're doing a straight all-audio mix. Effects and automation can be freely added, removed and tweaked without restrictions. And your CPU won't break a sweat, no matter how many heavy-duty soft synths you used.
The only downside to this technique is that it's a hassle to go back and edit the original MIDI, so I usually hold off until I'm happy with the MIDI, basic EQ/compression and starting volume levels. I'll also do some MIDI volume automation prior to bouncing, especially for orchestral swells and crescendos.