Uncapturing / unfreezing Synchronized mouse cursor

Windows 10 requires pressing "Control + Option" on my Mac keyboard to free the mouse cursor from its window. I have a mouse with an extra button that imd'd hoped to reconfigure for that combination keypress, but the best I can see is that you can set the combination as a modifier (which still needs keyboard input).

Id like to keep the keyboard shortcut but think it may be useful to freeing the mouse with a simple mouse button press.

thanks