Can you brake and operate gears at the same time with MTB Dual Control levers? The videos I saw so far show that with the same lever you can brake or change gears. OK.

But can you do it in the same time? For example you downshifting, lever is pressed down, can you start braking (pulling lever) without letting it go up?

Or in reverse, you are braking, you pulled lever already, can you also push it down without releasing the pull (braking)?

I have in mind MTB DC levers.
The answer is yes.  That was a complaint about the setup from many riders that often your would accidentally shift while trying to break.  The problem is worse when you are trying to brake while the front end is jumping all over the place.

I had a friend with the setup on a Kona Stinky Primo back in the day and I tried it on one shuttle run.  I decided it definitely was not for me.  I was told you can get used to it enough that the instance of accidental shifts is close to zero, but I am not sure I bought into that theory.