That looks like a DIR setup, so I don't think it's an option, but presumably yeah if you wanted to forgo the hose config and skip the SPG as well, you could further reduce the weight.Nicely done! Have you considered using an AIR 2 (or similar) and dispensing with the octopus reg and the 5'/7' hose on your primary. This will free up a couple of lbs, probably.
rx7diver