Re: little nervous .......
Add a box always after they are working 80% of the frames. If that is the case then add the box. If they are just hanging outside (bearding) to reduce the heat inside the hive they will move in when it starts to rain.
Would be nice if you were able to super for honey (assuming if you run a two box brood setup and already have the second box on). If you are adding a honey super give this a try. Prop up the inner cover with a stick or something (I use a small entrance reducer) which will raise the outer cover and give them a top entrance. Does wonders this time of year for ventilation and in my opinion adds in drawing comb out if there is a nector flow and plenty of bees.
Try living life with the attitude it's not about what you want to do but what you should do!