Had a few thoughts with regards to avoiding the gaze of a Navigator...
It would make sense that anyone who actively attempts to avoid the gaze of a Navigator suffers a few penalties when it comes to attacking said Navigator.
Sooo... Here's my thoughts.
If an NPC or PC declares that he/she/it avoids the gaze of a Navigator they are fighting, to get that +30 bonus, they should get a -30 penalty to all WS and BS tests against that Navigator, and to any Evasion tests as well - since they are actively trying to avoid a part of the battle field.
Also, reflexively avoiding the gaze without forewarning should most likely expend a Reaction.
The penalties can be voided by the Blind Fighting talent and/or possibly Unnatural Senses at GM discretion. Also being Blind makes you immune to Navigator Powers that rely on looking into the Warp Eye, unless you got some funky warp sight power like Astropaths.