But there are supposed to be people who turn the encoder as if it wasn't smart and then complain that not every turn is acknowledged immediately.
By "smart" you mean that the encoder response accelerates when you turn it faster? I only have an SDG2000X -- on that one, there is no dynamic acceleration, and I think I like it that way: One encoder detent equals one audible click equals one step up or down on the numerical digit. Is the SDG1000X encoder implemented differently?
I do notice that the SDG2000X encoder starts to miss steps when I turn it a bit faster. Which is not an entirely irrelevant scenario in my use: Say I expect the need to "tune up" slightly, e.g. to find a resonance, and then find that I am still further off than I thought. Rather than changing the cursor to a more significant digit, I just give the encoder a turn or two, which I can do blindly (while looking at the scope). In that case the encoder response becomes spotty, quite noticeable from the irregular audible clicks.
It seems that Siglent took a very conservative approach with the encoder debouncing. Still better than too
little debouncing, with the encoder making extra steps or moving backwards! But based on the experience with encoders in other products or my own designs, I think that they could have found a better balance.