I guess there's no harm in bumping this thread on a very helpful modification up again... Modified my DS1054Z today, with the same encoder suggested before (ALPS EC12E2424407). I can just second that the rotary knob is much easier to use for me now!
It's not just avoiding the sporadic additional step when pushing the button -- I had reasonable control over that, but it did happen often enough to be annyoing. But you also get nice haptic feedback when you want to rotate the knob a defined number of steps, e.g. when stepping down two channels while selecting the trigger input. Registering (counting?) the clicks happens totally unconsciously, but for me is much more pleasant than having to observe the display to see when the right selection has been reached.
On the other hand, the detents are subtle enough, so they don't become annoying when one has to rotate the knob several times. Overall, a highly recommended mod!
As a side note -- while I had the scope disassembled, I noticed that the screen is indeed protected by a glass plate, not plastic. I recall that this was debated in some other thread a while ago. A decent thickness too (approx. 2.5 mm), so Rigo did not skimp on this. Makes me feel better about having the scope directly on my desk, rather than on a shelf, while working with a soldering iron...