Crazy Floor Heater Thought?!?

Putting in floor heating in bathroom. Got Schuyler Ditra Smart thermostat.

When considering placement of thermostat the controller is pretty static - meaning you kinda set it and forget it. Maybe turn it up in winter and down in summer. And it’s all on a timer. So why do I need it out near main switches?!?

Could I put it inside vanity backing like the plumbing is. My wall switch is over top of vanity. So run the wiring needed for floor heater control straight down from light switch into cavity behind vanity and put in floor switch back there. It’s exposed through back of vanity. Am I genius Or insane?!?