Plane I currently fly, Pitot heat are with a manual switch overhead panel.
We have 3 differents caution warning (yellow) associated to each heating element.
We switch the pitot on, before takeoff and off after vacating rwy. If taxi is planned to be long in bad ground potential icing condition (Amsterdam rwy 36L for exemple), on cpt decision, pitot heater can be turned on for taxi.
Just to say, I don't see the problems of manual or automatic. If we forgot with the checklist, I ll have 3 big yellow warning. Takeoff without warning is a mandatory SOP in my airline. We will go only if a warning is already known and under MEL.