I feel the Initiative tracker could be updated where you can see who used their reaction as well as other things. Like tracking effects, could have counters on the initiative tracker able to add a simple label and put how many rounds it would last. so if a spell lasts a minute you can put on the characters initiave actually in the pop out box click their name, add counter, number of rounds, name it done. and just a little "R" you can check on the same tracker that they used their reaction and it goes away the next time the tracker comes around to that character.