Friendly fire adds a fun element to the game where you have to adjust your strategy, positioning and work together… It’s awesome… Leave recruit for those who want an easier experience. FatShark is awesome so I bet they consider this!
Friendly fire in veteran can also be like the friendly-fire-training-wheels training for champion
My recommendation would be to add it in all difficulties, but reduce the damage to 0 in Recruit and close to 0 in Vet.
There’s too many people in Champ that aren’t used to FF.