Fujitsu controls

I specifically have a Fujitsu air handler in this scenario but I have had this with Mitsubishi too. I have a wired controller for Fujitsu, the problem is that the homeowner wants to turn his controller down to 50 degrees. It only allows me to go to 60. I know the wall heads are able to go to a minimum heat mode. I’m trying to avoid putting a normal stat on this, thanks!