I have problem with my own defined shortcomands MOST of them do not work,??? Split beam (sb) does not work a legatobow comes instead.???

B T för beamtogether works and I have done the same…

S is the general shortcut for a slur, so I wouldn’t expect any command beginning S to work correctly.

B is the shortcut for adding a B (the pitch), but that’s only possible during note input (when the caret is invoked), whereas slurs can be added whether or not the caret is invoked.

so what letters should I choose I have tryed several …

a lot of letters are in use by themselves by default, so I would probably use them in combination with modifiers. (cmd/ctrl and alt, using shift only shift+letter is dangerous, because of the defaults for popovers).

For example, to filter dynamics, I have set a keycommand which is cmd+shift+f followed by d, for dynamics.

Splitting beams could be something like cmd-alt-b, or you could start every command concerning beams with cmd+b followed by s for split, t for beam together, u for unbeam etc…

I use a MIDI keyboard which frees up all the note name letters. A=transpose, B = beam, C= cut beam, E = remove rest.