I don't think the film will say much about Bill Bruford, but I felt that in his bio he was just being nice and quiet about it all ... rather than say something that would not seem right. In the end, the albums Bill was in are well remembered and the material is STILL played, and I think that says something about Bill's contribution.

It should be an interesting film, however, I'm not sure it will be that great, and probably be very sad considering how many folks were "there" and are not valued for their contribution. 

As far as having the "freedom to do anything you wanted" ... I rather doubt it, unless RF had open rehearsals where they could just go nuts at least once, just for fun, and to get the cobwebs and funny ideas out of the system, which is a really good exercise in theater for at least one rehearsal, and helps the concentration and dedication to the whole theme and flow of the piece at the moment. RF, is not exactly a person that did not do a lot of studying in his time, and his having been a part, and slightly involved in a couple of interesting things, would suggest that there were bits and pieces in it that he could use in the music or in rehearsal, or in the preparation of the music. Some musicians, don't like that and can not do this, since their ALL attention is on counting and the next chord ... but for folks like Robert he can go do the next chord, slightly different and no one will notice or give a damn ... because he does not lose his concentration or his step in the music itself. 

If anything, I expect the film to make it clear whose vision it all is ... and the folks that helped put it together!