I can tell you what works for me.
I have the latest OoZoon image in the flash, experimental 2.6 not stable 2.5
I run software update once a week.
I keep Barry Allen up to date { 4.8.21 at present }
Today I added Nabilo BH 0.11 to USB and it works just great.

Oozoon will keep your flash image bang up to date as long as you run updates via the software manager.

If you run your image in the flash without Barry Allen then installing the updates is easy.

Use DCC for e2 images, Navigate to the tools section and then IPKG packages and then upload package.
Navigate to your update and install.
Reboot the box and you are done.