I would heartily recommend this film. Here’s the promo:
youtube.com/watch?v=9OR0ckexTgY
I watched it on youtube (not realising it was up there illegally) a while ago and was really touched by it. I ordered it on Amazon (only ten quid) and watched it again today. 
I wonder what Tim Keller’s position is to UR. 
A really poignant point that the film brought out and that I’d always wondered about and which has UR implications is this:
Why did no one go to look for the prodigal son? Prior to Jesus telling the story of the prodigal son, He tells us about a lost sheep, and a lost coin. The sheep was sought and found, as was the coin. Why not the son? This used to bother me greatly as it undermined UR: it made me think that salvation is based on our having to come to the Father. So even if the Father wants us to come home, if we choose not to, then He allows us to be lost and that means we could be lost forever.
Anyway, I’m not going to spoil the film by telling you how this is resolved. 