Pretty weird. I wanted to see if I could get audio feedback from the Melodyne plugin (in stand-alone, you click on a blob and can hear the pitch as you move it around) -- I couldn't remember if I'd had that working in the past in SAW. One would need to have the audio engine running, of course; so I grabbed an empty mixer channel and assigned a hardware input device at the top of the channel strip. I was then able to enter live mode and test the Melodyine plugin for this. Alas, no sound. Oh, well.

Later, as I was working on the mix, I got the monitors up good and loud, and started getting some low-end feedback. Woops. I'd forgotten to switch that channel input back to "multitrack," and I have a mic always setup for voice-overs, so it was in the loop when the engine was live during playback.

I switched the channel input back and kept working. But the feedback persisted. Even with the channel input set to "multitrack"! It would feedback on playback, and I could manually enter Live mode, even though there was no visible live input set!

I thought I finally got it to behave, but the next day it was happening again, so I checked, and the channel input had returned to "Dev 01"! I switched it back to "multitrack," but the feedback still happened. And I can see the feedback deflection on the meter for that channel, so that's for sure where it's coming into SAW.

So, two things:

1) input setting won't "stick"
2) input setting won't actually change, internally, apparently

UPDATE: while checking the details in SAW for this post, I noticed that the MT was in Offset mode (I use Offset mode extensively when mixing music tracks). When I exited Offset mode, the "multitrack" input display for that channel switched spontaneously back to "Dev 01." I manually changed it back to "multitrack," and then was no longer able to get into Live mode, and there's no longer feedback during high-volume playback.

Note that I had a marked area in the MT. I'm guessing that's not at play, here. But I know a marked area affects the lack of updating to controls corresponding to non-marked automation while in Offset mode. Since the input setting is not automatable, I'm guessing it's behavior, here, is outside of the marked area issue.

Woops. I just tested it. The issue only arises when using a marked area. No marked area, no problem with Offset mode affecting the switching and display of the channel input setting.

I'll report back if any issues continue, but it appears that, like other mixer settings, what you see is sometimes not what you get when in Offset mode. Something to bear in mind.