That’s a pretty elegant solution for this scenario. Sorry to necro with my two cents.
If you find that your players wondering about what can be done dual wielding ranged weapons, just think of just how far apart two targets can be when you spread your arms. Narratively, you can have a lot of fun with two ranged weapons. Probably the perpetual dual wielder will spring for multi-attack specialist and pull off some action movie maneuvers.
You could put a narrative cap on how far one arm can twist and wrist can fwip in six seconds. Perhaps present it as “If only your pistol could get to your other hand in time”, allowing other extraordinary means to pull off this stunt, of course.
Mechanically, the multi-target rules handle this well imo. They don’t put a baseline cap on heroes playing twister with themselves, leaving it open for GMs and players to decide the reality in their game’s setting and narrative. I think I’d give circumstantial disadvantage when players need some world class agility not to get tangled in themselves.