The thing about "Paper Moon" is, it's a weird time for the Dominion to do any negotiating. It's the first of three "filler" episodes in the war arc, and the next one to directly address the war, "Field of Fire", shows it going very badly for the UFP and its Axis of Alpha. Previously on Star Trek, we saw a quagmire at Chin'toka, suggesting the UFP wasn't exactly driving fear in the hearts of wrongdoers at that point, either.
ST:INS tells us the Son'a were "known to have produced" Ketracel White, a substance supposedly only useful to the Dominion (note the tense). The DS9 episode "Penumbra" shows the Son'a are still at it, several months after "Paper Moon", suggesting ST:INS actually takes place after "Penumbra". It does stretch credibility that Starfleet or the Federation would be dealing with the Son'a at all if they continued to supply UFP's mortal enemy; at the conclusion of ST:INS, the Feds would be in a position to demand cessation of such things, and to get what they demand, again suggesting ST:INS concludes after "Penumbra".
Then there's the total absence of references to the Dominion war, which one could accept in a postwar situation but hardly during the war. The only thing our heroes are doing that could even remotely be related to the war effort is drafting new allies - but it's a mission Picard drops faster than his hair, and was going to drop anyway because his next scheduled task was a months-long archaeology expedition!
The only thing connecting ST:INS to an ongoing DS9 is the suggestion that Worf would be "returning" to DS9 if not for Picard asking him to take part in the expedition to help Data.
Does that mean the episode takes place before the DS9 finale (or its immediate aftermath) where Worf is about to leave the station for a diplomatic assignment? Not necessarily, as Worf might have plenty of reasons to visit DS9 even after accepting the ambassadorship. Although an Ambassador probably wouldn't be overseeing "Manzar Colony defensive arrangements". But then again, neither should an officer serving on DS9!
We never learned whether Worf really did become an Ambassador; the next movie doesn't show him in that capacity. Possibly he stayed on DS9 (or in other tasks sometimes relating to that station) for years after the end of that TV show, and ST:INS took place during those years.
Yet in the end, the stardate-free movie only offers one timeline fixpoint, and a tenuous one at that. This is balanced by dozens of hints that there is no war anywhere for our heroes to worry about, and indeed that anything possibly relating to the war is in the past now: Son'a are no longer the enemy, the Dominion is negotiating rather than fighting, etc.
Timo Saloniemi