Would it be possible to add the functionality to Dual-Box from one screen/character?

[Anethia]

I don't foresee this happening anytime soon. The technical challenges would be far too numerous to even attempt to overcome. The way it's designed each account/character logged in has to have it's own instance of PoL. It just seems to me the technical limitations of the 3 systems in question would prevent it. PS2 memory limits, and the by now famous Xbox lag freeze are 2 limits I can think of. PC might be able to pull it off with tweaks, but again I don't see it happening.

EDIT: it looks like what you want is being able to run multiple characters per account at the same time unless I'm misunderstanding. Again the system was designed to only run one character per account despite being able to have multiple characters registered to one account. To run multiple would require tweaks to the games entire foundation as well as the user interface. It's just not feasible with the current environment.