Here’s one of my favourite back carries for bigger babies (from about 6 months and up). It has 2 passes over the baby and most of the weight is on the carrier’s waist. It is a great one for longer ups. This carry requires a base-1 wrap. I’m using a base + 2 wrap here. Have you tried it?
The Candy Cane Chest Belt is comfortable versus a traditional knot and pretty too!