I tested my Loki Levity Jacket's carrying capacity on this climb.
I had NO PACK, only my jackets convertible lumbar / daypack "N-Pac" design.

Without a separate pack I was able to carry;

2 liters of water
1 micro fleece top
1 loki softshell pant
4 energy bars,
1 camera
1 multi tool
1 small roll duct tape
1 tincture tea tree antisceptic
1 bottle sunscreen

I saved the weight of a day pack on the backpack in. The N-PAC worked great on this climb.

Do more with less. Is that why its called a "lesson"?