I feel like I'm going to come off as a Diafine hater but I'm really not. However, this is one scenario in which I don't see why one would want to use it. Yes, it's a remarkably convenient developer, but it's not particularly a high acutance one. And while not everyone wants that, I personally feel like shooting a low grain film like Pan F just cries out for edge effects, adjacency, and acutance.
Just a random comment. Seriously, I have nothing against Diafine, and I haven't even used it myself. Just babbling.
allan