OK, after some testing, flak & blobs are ostensibly affected by the status of the weapons' subsystem.
Beams are also affected, but in a somewhat different way :
- Even with a destroyed subsystem, they still have a chance to hit their target
- When the dice says they miss their target, how much the beam if off target depends the weapons' subsystem's health, much like projectile weapons
- It feels like the beam is more likely to hit when weapons are at full health, although it could simply be that the beam "misses" close enough to the target that the beam hits it anyway
tldr; All turret types are affected by the weapons subsystem's status, but beams get an extra dice roll.
Also, this is completely unrelated, but I apparently need to appologize to the SNTC folks :/