Giant 20' x 3' x 2' router build

[JAZZCNC]

I guess if I just use the m4 code it tell me if we wired it for it or not already?

Yes and it's likely not.! . . . But Charlie be aware that these spindles are not designed to be run in reverse.? They can unscrew the collet running in reverse if the forces are high.
In your case I think you'll be ok but still make sure you really tighten the collet.