You are correct this is not listed in the manual.
Check out the switches on the back of the button bank. One of these putsit on free play, I can not remember if it is the far right or far left (it is one of these) only change the switch over one at a time.
Actually you pointed me in the right direction. I found the "premium" switches described in the manual; one for each row of buttons on the back of the button bank, plus a fifth that is a test switch, ". . . which can be used for a free play switch." That should do it.