I've seen a lot of people getting frustrated about getting "third partied" in hourglass. Even to the point of demanding some sort of protection from it (like moving hourglass fights to a separate server). I don't think anything should be changed to stop hourglass fights getting third partied, but I do think there's a simple solution which might help make it a less frustrating experience.
What if there was some sort of commendation for winning an hourglass fight even though another ship (third party) fired on you during the fight. This would mean that getting third partied would provide an opportunity for achievement, rather than being a purely negative experience.
I think this would help players change their outlook and mentality about the experience, and combat a lot of the frustration they feel, without actually changing anything about the game. e.g. another ship starts firing on them and instead of thinking "Ugh, now I'm getting third partied. This sucks.", they think "Ooh, I'm getting third partied, this is an opportunity to get my '2 for 1' achievement."
