Looks like Rhapsody has an ability I didn't know about which lets you consume your +3 from Scarlet Remittance to either guarantee a crit, heal yourself, or give a target disadvantage on saving throws.

https://bg3.wiki/wiki/Scarlet_Feast

I still think which one is better depends on how many spells you're going to be casting.

If it really lasts until a long rest thats pretty good. From 2 stacks onward the damage output should be better. +2(3) atk roll and +2(3) dmg vs +5% crit chance and ~+0.67 dmg from Organ rearranger