I think it would be better to add the 5E "delay action" to the game than simply delay a turn. I can imagine my thief holding a dagger stab and my fighter shoving an ennemy in their melee range after hitting them.
That sort of combo-ing would be so satisfying to pull off
+1 to that, although I haven't seen this on interviews I imagine it's something they must have in mind for full release, as it's a pretty big part of available actions. It's hard to implemented because like the spell command it's so versatile, command they made Just one possible word so far, but I expect more might be added, just like different delay actions should be consistently be added down the road
