Hi thornfish,
Welcome to the forum.
What is the target total size for the trees ?
If you want them under 2m/7', then yes, you need to constraint their roots.
If you want them higher then let them roots run free.
I'm using 80liters/20' containers ( trashcans ) on some and the trees stay smaller with closer inter-nodes spaces. So definitively, handy BUT there is a huge drawback :
You'll need to water them or they will fry. The soil in the container won't be able to wick moisture from the surrounding dirt so a drip system is a must have especially
in your hot climate - at least a good watering schedule is needed to keep the trees alive and in production.
For your wall ... is it strong ? Because the roots of the trees will test the strength of the wall and try to pass through ... which leads you to cracks ...
In your climate, you could use the espalier method or the "total die-back every 4 years" method ...
I would give it a try and see what comes out of that !