I simply don't know about BR files. They are so much larger than standard DVD ripped files. I know it will do fine on mp4 files, but about others I am not sure. Someone who has either tried it or successfully done it will have to reply.
I personally would have doubts because of the lower transfer speed of the NV+ (25MB/s) versus the Ultra/Pro series (60-100MB/s). It would be a close thing, as even at the full speed it would take 23 minutes to transfer a 35GB BR file. At a more leisurely 12MB/s (allowing for some glitches) it would take 49 minutes. I am using 35GB for the size of the BR file, for the only BR disk I have access to has 35GB of data on it. (It's not my disk as I don't own any, and borrowed it to test a BR drive).
That would be like trying to stream 5 DVD files, and I am not sure the NV+ can handle 5. One or two, yes. If you are definitely going to need to stream BR files, you would be wise to do some more research before committing.
Remember - the NAS is not a backup plan.
Backup = Good, No Backup = Bad