That's weird that you've lost WPFM in Wakulla. Did you only loose reception at your house? Can you still pick up PFM driving around the area?
I know next to nothing about FM engineering but I believe I remember all broadcast antennas have a null somewhere even when classified as omnidirectional. Most engineers find this null and use it to their advantage. If you aren't in a nulled out area there must be a hill or ridge between you and the new tower. That extra 400 feet HAAT should improve car reception in Wakulla while sacrificing indoor reception. My observations up in Decatur county were all from low end factory Mopar or Ford car radios.
I know next to nothing about FM engineering but I believe I remember all broadcast antennas have a null somewhere even when classified as omnidirectional. Most engineers find this null and use it to their advantage. If you aren't in a nulled out area there must be a hill or ridge between you and the new tower. That extra 400 feet HAAT should improve car reception in Wakulla while sacrificing indoor reception. My observations up in Decatur county were all from low end factory Mopar or Ford car radios.