This guy would be a good use of Trigger Defeat- instead of the enemy having to kill him for him to blow up, he could blow up as soon as he reaches his target.

Yeah, or maybe Self-Destruct Sequence. There isn't even a penalty for walking away from him. The only time I'd take the Self-Destruct is if I had a Triple attacker who needed to land two shots on something to win the game, and this thing was adjacent. Then I'd take the 20 damage to get to use my other two shots on the actual target. A Muun could detonate these guys, and that'd be fun, but yeah, they really need either an incentive to hit them or a way to detonate themselves.