I have completely stopped starting focus sessions manually because of the annoying notifications and notification sounds. When starting a focus session, I usually am already in the topic and these notifications and sounds are just unnerving.
Being able to change the sound (per notification type) would also be great. I hate these sounds. They also broke my focus too often, especially at the end of a focus session timer where I was still working on a unfinished thought.
Make notifications more graceful and less annoying please XD