Bushwalk Australia

Just general spitballing question.
When I was younger all of my rucksacks had external pockets, when I had saved enough to buy my first modern rucksack the extra pockets added cost so I got the Mountain Mule copy without the pockets and I missed it greatly.
Over the decades I have had several packs, some with and some without pockets.
Also have many detachable pockets to increase capacity, including the WE back pocket and the old side pockets.
In general I've found most add on pockets too small to be really useful but I like them to keep the XPD stove fuel bottles in to stop possible contamination of the rucksacks contents.
The WE back pocket holds two fuel bottles which is a reasonable quantity for a weeks snow camping with a lot of warm drinks but not much else apart from the stove base.
For those of you who like back pockets do you like and prefer one large wide pocket or twin deep and tall pockets and why?
Possible a new rucksack project in the pipeline as I've just found a big piece of CoreDux canvas in my stash and why I'm also looking for a CampTrails external frame

Front pockets are much more useful, in my experience. Depending on how the main pack is constructed, it may be possible to attach Aarn pockets.

For load balancing definitely but I'd not carry Shellite on my chest no matter what bottle it was stored in, also back pockets can be much larger in size/ capacity. I find that the Aarn Expedition front pockets I have are too large for my personal comfort and therefore I have not used them much. Shoulder strap pockets I do use but they are relatively small at 3 litres, great for the sunglasses or goggles