I used to put the mastered .wav to Logic Pro X, turn off circular panning law and render in mp3. Although this required quite a lot of steps because if you want to go from 88,2kHz to 44,1kHz, you need to re-render the .wav into the different sample rate and after that render to mp3.
I have since moved to iZotope Ozone 7’s own encoder, I just render out .wav and .mp3 from there. For conversion to .m4a I use iTunes directly (Create AAC version directly from the .wav source file).