3 nights in Yellowstone mid-July

My son wants to see Yellowstone among other things so we have a trip planned for the first 2 weeks of July. I know we’ll arrive July 10 and depart July 15. I hope to reserve a car camp site the first 2 nights while doing the normal touristy stuff so we’ll have 3 nights to backpack somewhere. Preliminary research and advice has suggested Skyrim (depending on snow levels), Black Canyon and Heart Lake/Mt. Sheridan.

The Skyrim Trail would be right up MY alley though it would be just 2 nights. It appears to me it would be best to go up Specimen Creek to WE5/WE7, across the ridge next day to WF2, and then out to the road for 4 miles back to the car.

For Black Canyon, if anyone has made a loop with Rescue Creek (some claim site 1A2 is really nice), which direction is best and where did you start/end? It appears to be almost 4 miles of road walk from the USFS campground to the RC TH.

For Heart Lake, I’d probably loop around the lake as well to extend the trip. It seems 8J1 & 6 are the best sites on the east side. Any comment on the 8B_ sites south of the lake? Is there anything cool to see south of the lake? Soaking in the spring-fed river west of 8C1 is too far out of the way I think.

Where would you go with 3 full days at this time? He will have final say, but I’d like to present the best options to him.