Ive noticed a lack of ASTs actually using CO unless its only AoE card buff, and people saying it has no utility(yeah it could be a better skill but still, play with it more at least people)

More things you can use it on
-AST refresh (It shares the same CD as CO/thats two more refresh ticks for MP)
-Lightspeed
-Extending your buff with your synastry target(they must be in it)/Extending your own card buff on yourself