These days I find I just don't have the time to fly around to the cheapest commodity vendors for a particular doff mission- I just tend to replicate the ones I need on the spot. But it's an annoying and, as I realized, ultimately needless song and dance.
Why not, instead, add an 'auto-replicate' button to the doff menu that pops up if you don't have the required commodities but are able to replicate them.
So like "You don't have commodity X, Y, replicate for Z Energy Credits?" and then launch the mission.
Juggling commodities are trading them is intended to be part of the duty officer system, so I am reluctant to make it so easy to replicate that it might as well just be an automatic EC cost.
That being said, the juggling of commodities should be at least somewhat interesting, so I am open to ideas to make the juggling of them more rewarding and/or more interesting.
I don't mind replicating stuff, what I mind is the replication interface, which is clunky. At least for me I end up squinting at the screen while scrolling around looking for a tiny little icon which is always a chore. Granted, I always just use my ship replicator, so it isn't like I'm really doing what you are 'supposed' to do anyway.
I'm not smart enough to come up with a solution though, short of integrating your voice chat system to let me ask the replicator for my materials. Which would be awesome.