I did the change back in the spring when I put the carbs back on. I used a filter for a Yamaha outboard on it. It is nice and compact and has a rubber boot over it, so it hides it pretty good.Nah, no reason to do that when that fuel valve is a somewhat ugly octopus and the tops of the carbs look so much more round and pretty. If anyone even bothers to look in there.
Maybe on a museum bike but those are definitely a slim minority of UJM's in general.
Remove the sucker, cap the vacuum port, and run the fuel line straight to the carbs.