Also, are your mattes coming in 1 or 3 per DPX sequence? Starting with 8.0 Resolve supports using the R, G, B channels for three separate mattes... I honestly have never had a reason to figure out how that works, but sounds like you could ask your compositors to provide them that way... It's very common to do that in Nuke, right? Best case scenario you could have one third of the mattes...
KC
Prehistoric Digital
PhD Grading Suite