Okay, after a week of regular use, I don’t have much to complain about, but:
a) One small bug: Create two file groups, rename the second, delete the first, and the renamed one reverts to “File group 1”. Slightly annoying.
b) Could a fixed (minimum) of master section slots at least be an option? As it is now, you have to either plan ahead, or add and then move a particular plugin. The previous method of simply leaving a slot empty in case you wanted to insert something just fit my head better.
And that’s it. Which means I’m still impressed.