I have a variety of 5040 and 5030 spare props.  The need for both CW and CCW props, makes for a mess when trying to find a replacement when you crash and need a new prop. Given I break at least 1 prop per flight (I’m learning flips these days!), I wanted a quick way to access either size or direction of prop.   Look no further to your LEGO Technic collection for axles (or go get some @ Bricklink).   Depending on the # of props you want to have in your parts box, you can use a #10 or #12 axle with some Technic bush units.  You can also use axle extenders to combine units (i.e. you want CW and CCW separated).