Board Thread:Question and Answer/@comment-24596086-20150324191911/@comment-25435121-20150402173558

Oh, I misunderstood. Yes, the Assist in that manner is automatic. Most people think the card chosen is based on which one has the highest attack and is in the comrades attack unit.

As far as we know, the answer is "no" to waiting on opening boxes. The changes should be the same as opening them right away, but this really gets more into how well Nubee has implemented their random number generator and it's effects. As far as I have been able to tell, there is no difference.