I am using Shadowed Unit Frames and wanted a simple text indicator for tracking Burning Ember bits when out of combat (I'm using Affdots in combat and it's hidden ooc). After some research I made a following custom tag:
local power = UnitPower(unit, SPELL_POWER_BURNING_EMBERS, true)
So if there are other locks using SUF and your other addons don't show ember bits, you can use this tag. If you don't add "true" after "SPELL_POWER_BURNING_EMBERS", it will show whole embers (0-4) not ember bits (0-40).
When creating a tag, make sure your "Events" value will be "UNIT_POWER_FREQUENT" (SUF should automatically detect this).