Is it possible to "override" Mac's system-wide shortcuts?

[NOTE: See the edit at the bottom.]

I'm using MuseScore 2.1.0 (revision 871c8ce) on a Mac (macOS 10.13.3). I want to include verse numbers in lyrics. I found out how to do so from a previous discussion (https://musescore.org/en/node/45486), which involves entering a space using Ctrl-Space. I'm guessing that those instructions are for Windows, since on Mac that does nothing; also, I assume that the Mac equivalent would be Cmd-Space. However, since my Mac has that as the system shortcut for opening Spotlight search (as a default), it seems like I'm simply unable to enter a space when entering lyrics. Is there a way to "override" the system-wide shortcuts so that I can add a space while entering lyrics?

I realize that I could technically just edit the shortcut in MuseScore 2's preferences panel, but I can't even seem to find it in there. I've also tried adding a shortcut specific to MuseScore 2 in System Preferences, but that doesn't seem to work, either.

(This also goes for MuseScore 2 shortcuts that use the function keys. On my MacBook Pro - and I think that this might be different for other types of Mac keyboards - the function keys have system-wide primary and secondary functions, such as F11 being both "volume down" and "show desktop." The secondary function is accessed by pressing the Fn key at the same time, which means that I can't use Fn-F11 to open the Play Panel, even though that's what the MuseScore handbook says. Even switching the primary and secondary functions in System Preferences doesn't help. And, again, adding shortcuts specific to MuseScore 2 in System Preferences doesn't seem to work.)

EDIT: Never mind about not being able to add a space in lyrics on a Mac! I found out that the actual shortcut is Opt-Space (not Cmd-Space) via another previous discussion (https://musescore.org/en/node/2064). But my question still applies in the case of being able to use MuseScore 2's shortcuts that involve the function keys - though that's not as urgent, since those can be accessed manually through the menubar.