I had the original posters question come up in a game today. Found this thread when searching for an answer.

I’m an inexperienced player but the few games I’ve played I’ve treated Maximum Firepower as being beyond range 3.

I was playing a more experienced player today and was told that it was not inclusive of range 4.

Has anything changed or is Maximum Firepower and Coordinated Bombardment still simply beyond range 3?

You're right. The first number on the range band is the minimum range. So at minimum Maximum Firepower must be used at least at range 4. Otherwise no one could fire a blaster at range 1.

@drail14me