Using these two macros, I'm hoping to effectively turn the Caps Lock key into a shortcut for cmd+opt+shift, effectively creating a new modifier key:
By disabling the native Caps Lock usage and using a combination of the Keyboard Maestro debugger and macOS Keyboard Viewer, I've confirmed that it's working as expected: pressing and holding the Caps Lock button triggers the Caps Press macro and presses the correct three modifiers, and releasing it triggers the Caps Release macro and releases them. See here:
However, third party applications (in this case, Alfred) are not picking up shortcuts bound to that modifier pair (in this case, ctrl+opt+cmd+space).
I advise you to look into Karabiner for this.
Here is how I use my caps lock, it is quite similar to yours but only for opt+control modifiers.
Actually, I’m trying to simulate that exact Karabiner behavior. I’ll need to be using macOS Sierra for a bit for some software testing, and it isn’t compatible, and seems like it won’t be for some time. My caps lock muscle memory is strong enough that I’m pretty desperately seeking a replacement.
Unfortunately, it doesn’t look like this is going to work, you’re one of several of us in the same boat with the same idea.
@nikivi that is one seriously impressive Karabiner setup, going to need to take a close look at it once Karabiner is ported to Sierra.