I can see how this is useful but I’m afraid it’s a bit of a risky feature.
Since this is a knob you’re likely to give a big turn when using it for other functions, a mistake is easily made (shit, thought it was still controlling the delay send) and whoops, you’ve raised the master by 20dB.
Like always, I’m not against adding this as feature for professionals and skilled people.
I’m generally against ‘dumbing down’ professional products, just because amateurs might operate them.
Don’t hinder professional users of professional products, better to create additional ‘novice’ modes.
In this case it’s the other way around. It seems to be a product aimed at amateurs with some professional use in mind, so I’m just saying: be careful what you wish for.
I’d see less risk in permanently assigning one of the smaller encoders to master fader duty.
That said, as a professional sound engineer, the master fader is among the controls I use the least. It’s mostly set and forget.
Then again, I usually have groups and DCAs at my disposal, so in this product I can understand the desire to have the master fader control handy. This product should obviously be amateur friendly.