So that rock wall plan isn’t fully supported by the joists. A lot of the weight is held by the studs and floor it’s resting against.

I’ve built two separate home climbing walls. The biggest lesson I learned was securing it against the wall is really important. The swinging forces generated by climbing won’t work if it’s just supported at one end. I tried to build a freestanding wall and it was impossible to make fully secure.

My current wall is small, one 4x8 sheet of plywood. I have 1 4ft 2x6 for connecting it to the wall and one attaching it to the joists, each are secured to 3 studs/joists. This is very stable. I’m like 150lbs and I can make dynamic movements on it all day and it doesn’t move at all.