Having a company phone with you at all times and blocking the signal is useless to a boss trying to call you. What’s the point?
"Gee, sorry, I missed your phone call / Gee, sorry, I missed your email. Gee, sorry, I must have been in a spot with a really bad cell."
Personally, I refuse to deal with trivial garbage outside of business hours.
If it is possible (it may be, I don’t know. My cell phone is an antique) set the work cell phone to forward to the private cell phone and then leave the work phone at home. They can still reach you but can no longer track you.