That's a really good question. The answer is yes and no 🙂
No, there is no real dedicated way to suspend MIDI automation. You can disable MIDI Draw view, but that is strictly a visual thing, it is still there and still sending out the MIDI messages.
So now onto the Yes part of the answer. You can separate the MIDI draw data onto a separate region playing back through the same channel strip. That way you can either mute/unmute the region. Or use the power button to toggle that track on/off.
Here's a relatively painless way to do it:
1. Hit Control Shift Return to create a new track assigned to the same channel strip.
2. Copy your region down to the new track.
3. Delete all the MIDI notes from the newly copied region. Maybe rename it something like "MIDI CC only" or something like that, just so you can keep track of what is what.
4. Delete all the MIDI Draw data from the original region. Maybe rename it "MIDI" Notes only" or something similar.
That's it. Now with the two regions separated you can experiment freely. You can even use this method to try out multiple MIDI draw variations. Just keep creating new tracks assigned to the same channel strip. Create an empty region on the new tracks with the Pencil Tool. And then create MIDI Draw information in them.
If you want to actually look at the notes at the same time, maybe open up another MIDI editor showing the original region with the notes only. You can create a screen set for this if it is something you want to do regularly.