Has anyone "mathwing'd" the buzzsaw set up vs. straight focus? Just seems like something that needs doing.
Not really a need to. The Target Lock of the Gunner'd shot is identical, statistically, to a Focused shot.
However, the glory of the Buzzsaw set-up is that you don't need to have performed an action to be effective in combat.
If you're stressed (or boosted), you're still fairly well off against any foe.
Considering that the Shuttle needs to boost fairly often to be effective at maneuvering, you'll not get to focus very often.