When the WCS support was written we didn't have any temporal operator support so we couldn't leverage a time period even if provided. That probably isn't the case any more but this isn't the bug to track it with. So, from a documentation standpoint, as you suggest, comment out any mention of timeperiod metadata until the support is added. A WCS timeperiod bug could turn into a documentation bug at that point.
As for rangesets I've got to go back to my original demos. Those are used to describe image "bands" correct? I've got a demo at the DNR that allowed users to choose different bands that might be helpful here. I just need to find it and dust it off.
Steve
