Sorry if this is a repost i searched "abyssal shelf" and only got one threat about flight path resetting.
But If your having trouble getting all the guys for the quest you can easily just put the bomb on your action bar, for example 1, and hit 1, click, hit 1, click,
You can send out about 4 bombs (my max so far) and all of them will explode, i have tried this with other bombs but most just register one hit except for this.