Customize keyboard shortcut?

Is there any way to customize the key combo to launch TinyGrab? Sadly, the default Cmd+Shift+4 is already in use on my computer and it's not something I can change - and you don't even offer an option from the Menu Bar icon to launch it from the icon, so the program is basically useless.

Would it really be that hard to offer a Preferences option to customize the shortcut, or a menu option to "Start Capture" so we can set our own custom keyboard shortcut via the Mac system preferences?

Or is this one of those "undocumented features" that takes a brain surgeon to figure out, because it definitely is NOT on your FAQ anywhere.