There's just one or two issues with this method. One is you can't possibly know what aperture you're gonna need if you want precise DOF,(and sometimes using a lens at its smallest aperture is not the best solution with macro as you get diffraction) and Two all that removing and replacing of the lens is gonna introduce dust onto the sensor. Much better to get a $2 coupling ring and attach a shorter lens in reverse onto the front of your main lens. Problem solved as you have full control again. You just use the aperture on the reversed lens to get the DOF you want.