As it seems you know, long straight walls are not ideal. Adding a few curves would help, but I am assuming you want to maximize space along a straight property line.
Adding buttresses along the wall would be another option to reinforce. Such buttresses could potentially be multifunctional. For example, a 4 foot deep raised
garden bed formed of earthbags on one side would add some stability to the wall. A shed,
chicken coop or mini-greenhouse built between buttresses. A
cob bench or outdoor dining table. Tea or meditation room?
In the big picture, it doesn't sound like the wall will serve a structural purpose in your home, so it probably doesn't need to be heavily overbuilt. What's the worst that happens? A 10-foot section starts to lean and eventually falls over?