A nice touch: If I have Rhonas the Indomitable in play, and I move to combat (from my precombat main phase) while having mana to activate his ability, MTG Arena stops on the beginning of combat step rather than going to the declare attackers step so I can activate that ability and buff another creature to 4+ power if needed to attack with Rhonas.

I just wish they did the same thing with Trostani, Three Whispers so I could grant creatures vigilence immediately before declaring attackers. Maybe I should file a bug report...