Okay, so I've been trying to piece this one out. The FAQ for the main rulebook and for the Tau codex does not cover this situation in the slightest. In fact, GW FAQs seems fairly useless due to lack of content.
The question is, what BS does a seeker missile use to hit a flier when a marker light token has been used?
Does it need a '6' to hit following the rules of snapshots? or does it need a '2' following the BS 5 that a seeker missile gets?
I am learning towards a '6' since the main rulebook states that a special rule must mention snapshots in order to modify it. The rules for seeker missiles don't include any mention of snapshots.
I do think you could spend marker lights to increase the BS of the unit firing at the flier, and the seeker would also benefit from that as well. So for instance, you have a hammerhead with two seekers on it. You get four markers on a flier. The hammerhead can spend two points to launch both seekers, and then the other two points to get a BS 3 for all shots at the flier.
Is this how the rest of you would play this?