Am I interpreting this combo correctly as being able to use the sneak attack twice as part of an Action Point Nova? (formatting is wierding out on me, apologies for the bold)
Sneak of Shadows [Multiclass Rogue]
Prerequisite: Dex 13
Benefit: You gain training in the Thievery skill.
Once per encounter, you can use the rogue’s Sneak Attack class feature.
Prerequisite: Rogue, Sneak Attack class feature
Benefit: If you spend an action point to take an extra action and have already dealt Sneak Attack damage during this round, you can deal the extra damage a second time during this turn.