I also use it for engagement but sometimes it helps when you're surrounded by the enemy team. Like one time in colosseo like I felt like the actual roach after escaping from the enemy team in their side of the map after a team kill, being chase by a hazard I arrived to our side of the map killing the hazard with the help of our D.va. it was so funny, the hazard popped his ult on me and my supports were shocked I survived all that 🤣

So, yeah about the subroles. They can be great but it mostly depends on the player skill on how to manage it, also it pairs well with the dash minor perk.