KMST 1.2.410 - Skill Changes

Assemble Crew was given data for each individual summon. Each summon was given a new effect from Crew Ship Commander. Old effects were garbage. New effect is +10% Weapon ATT while one us summoned, Muirhat - Critical Damage +10%, Valerie - Critical Hit Rate: +10%, Jack - HP/MP +20%, Speed +20.

I don't think that's what it does. From Google Translate:

# v% increase in damage of the crew summoned, if the crew is summoned Increases Physical Attack # pad. \ n

v% = 10% (value wasn't changed in this patch) meaning that it increases the crew's damage ("+10% increase in damage of the crew summoned", not "+10% increase in damage when the crew is summoned"?).
#pad = +30 atk, so you get +30 atk when you summon the crew.

Doesn't make much sense to give you both +10% damage AND +30 atk. This way, it buffs up the damage of the summon just like Satellite Safety / Robot Mastery.