I tried for the first time Step Input and feel that can not be the right way:
The same with the virtual keyboard.
Am I doing something wrong?
Indeed, that doesn’t look right. Step Input should enter notes at the position of the playback cursor when Step Input got enabled.
It would be interesting to get a copy of your project showing the state with the nested tuplets in bar 155.
score_tests.zip (746.8 KB)
very happy, thank you Stefan!
I haven’t been able to see the empty nested tuplets, but I’ve got an idea why you don’t see the input: You need to make sure, the score editor actually shows the position of where you are entering with StepInput.
In your screen capture, you probably only have that second slightly longer midi part in track “treble 1” selected (bars 158 onwards), but the project cursor is sitting at bar 101. If you also open the key editor in the background, you can see what’s going on.
To fix that, you can:
- manually extend the midi part to start earlier
- include the previous midi part as well, since that also includes bar 101
- create a new layout with this track, which will automatically contain the range covering all parts in the track
- put the project cursor at a position shown in the score. You can click a note or barline, press L
I tried a little further with your advice.
Gluing or extending the parts didn’t help.
Selecting the part in question didn’t help either.
A new layout didn’t help either.
BUT:
The step input starts and ends with the left and right locator. 
(Ctrl Num 1 and Ctrl Num 2)