On first game load every projectile will have an "enable config" config. They do not appear in Risk of Options menu. Close the game and start enabling what projectiles you want to configure, after that launch the game and all enabled projectiles to configure will have all available projectile configurations. These configs do appear in Risk of Options menu.
Currently there are configurations only for ProjectileSimple, ProjectileExplosion, ProjectileCharacterController, ProjectileOverlapAttack, ProjectileSteerTowardTarget and BoomerangProjectile.
To add a compatibility subcscribe to GetProjectileCustomConfigs that will run during projectile configs generation when config for projectile is enabled. Gameobject argument will spit any projectile, so expect that it will not have projectile component you want to configure. There get your needed component, check if it is not null and create configs. Please create configs either by using CreateConfig mthods of this mod or bind from this mods config file to keep projectile configs in this mods config file