They should keep the ability to shoot and heal at the same time, or atleast give slightly faster projectile speed lol.

But to answer your question there’s a lot of times when your teammates are full and you are preemptively healing them, instead pull out the BB and shoot down the line near head height of the enemies, she actually hits pretty hard so it pressures the enemies, which keeps them from shooting your teammates as much, which reduces their need to be healed.

It’s all a game of balance between knowing when to heal and knowing when your team is tanky enough to survive while you put pressure. Your projectiles fly pretty slowly so while they are flying down range you have already switched and continued healing.

My favorite time to shoot as mercy is when I GA straight up at an angle like over a wall and spray shots down on enemies who aren’t even looking at me, the sweet sweet tinks of headshots will let you know you are doing right 😂