Diafine literature specifically states, ""Diafine can accomodate as much as a two stop increase over the recommended indexes, without serious loss of quality
Why not give it a try? Of the three devs you have, this claims a two stop increase...
*I've never tried this, so it might not work at all, just wonder why you dismiss Diafine so fast when it claims to give two stops, but maybe it is one of those films that cant be helped with Diafine....I dont know...just currious as to your thoughts on it not being of any help????*