How to restrict a field from technicians

We are having issues with technicians raising the priority of a ticket. It is critical that only a specific set of people have this ability, because it launches our Major Incident Management process, and shows up on management reports. Is there a way to restrict technicians with edit access from being able to set this field? I was thinking of removing most of the technicians ability to edit tickets. Not sure if this would restrict their ability to enter tickets, though. Also thinking of setting a business rule or python script to throw up a popup message if those people try to update that field.

Is there a better way to do this? Can field restriction for technicians be a feature request?

Thank you.