I was under the impression MIDI always had to be Frozen, or bounced (basically converted to a WAV file) before it could be Audio Exported.
See image for what tracks are selected, then, Audio Export> 48/24
The result is MIDI drums also being recorded.
I'm not sure this is a good thing. What is the benefit of freezing tracks if MIDI drums can be Audio Exported realtime?
https://lh4.googleusercon...UMS_During_Mixdown.jpg
 
 

There has never a requirement to freeze or bounce MIDI before export. Rendering audio before export can be useful though. It can reduce CPU load, at the expense of I/O. It provides an unchanging version of the audio, especially useful if the synth has some randomizing element. Some just prefer to mix using all audio tracks, a workflow thing.

No you do not have to freeze or bounce MIDI tracks before export. The benefits of using freeze or bounce is to cut CPU usage. i.e. as a project grows so do CPU usage. Take a large project add a MIDI you may notice notes not playing or skipping. This is why one would use freeze or bounce.