Kilana, Weyoun, Quark, Morn, Garak, Seven of Nine and Vic Fontaine are (among others) the lucky ones who don't have to wear dress uniforms.
The Doctor (EMH) could simply modify his uniform without having to change into it. He is unlikely to feel uncomfortable. I'd like to see the Doctor in the white dress uniform....![]()
As would I, Kilana2. I would far rather have seen everyone wearing them consistently. Why reprise TNG uniforms in the first place, and why grey them down in later DS9 episodes? I always found that rather silly--uniforms can be grim enough as it is without being made mostly grey! (Again, see TOS uniforms--both standard and dress--for a counterexample.)
I gather that those named in your list don't have to wear dress uniforms--or indeed any uniforms at all--because they aren't members of Starfleet. And even if he were in Starfleet, Vic Fontaine always dresses in character; that's his uniform, if you will. Odo and Kira dress to the nines when they visit him, because they, too, are in character at such times. Not that I'm telling you anything you don't already know!
