Fly mode Radius

I don't think you can.  I remember seeing here long ago that the radius was fixed.

OK, that probably explains why I can't find it. Thanks

there was CODE you could put in the program, but it had no effect on the radius.

FLY/ON,3

but changing the 3 would have no effect.  MAYBE they have changed it, but I don't know.

See I seem to remember the same thing (back from 2016 days) where it was FLY/ON, .118 in our case for inches.
But back then we disabled that "cool feature" the first time it clipped the corner of a part and boss said "NOPE!" 

When looking today at 2020 there is no radius size. 

You are correct, in older versions this was available

I was told by Hex AE that the FLYMODE movement during execution depends on your controller and how fast your MOVESPEED is set at. Several of my older programs I had to move the MOVEPOINT another MM or two to clear the part because of running pretty fast around the part.