(1) I think a few might have appeared in early 2020 (as the lockdowns messed with business). I know that AS ran a few, and I think the others did as well, since the requirement to maintain service at various locations with mostly-empty planes meant that it made more sense to (for an AS example) run a "tag flight" SLO-SBA-LAX or something similar.

(2) A few years back, I was on the same plane/same crew MCO-ATL-CLT-ATL (low-cost status run). By the end of it, they had my PDB to me as soon as I sat down.