Notion needs additional functionality when it comes to shortcuts.
First, it would be helpful to be able to make shortcuts for menu items that do not have key bindings. (Score menu > Full Score Options... and Parts Options... for example). On a Mac, at least you can use the system level App Shortcut functions to fix this.
Second, there are some edit commands that can only be found in a right-click contextual menu. (with some notes selected, the Notes and Tuplets commands, and all their options become available, for example). These are not available to the MacOS, so no shortcut workaround is possible. It would helpful to have these appear in the Notion menus.