Originally Posted by
diburning
Overhead space is reserved for Comfort+ (supposedly) but it doesn't say anywhere that other Comfort+ passengers can't fill it up, causing you to need to check a bag, if you board after Comfort+ boards full. The Comfort+ bins only span the Comfort+ seating section, so they still don't have enough space for all Comfort+ passengers (but this is almost never a problem because Comfort+ passengers still board before regular economy and would simply overflow into the regular economy bins)
Let's take it from the top... FAs start by filling closet space and overflow into First's bins as needed. First passengers fill remaining F bins and overflow into Comfort+. Since DM's can board early, they take whatever bins are available as they walk to their seats. Comfort+ passengers boarding early take whatever space they can get. Comfort+ passengers boarding late may or may not have any space left for their luggage.