Yes, that's basically it. I personally would probably use it as a non-extended line, to keep track of the period's end and starting point based on the line's lenght. But maybe some "extend line" options would still be helpful when using it on higher timeframes. Also, the option to pick pieces of information that'll be shown in the line's label would be great. I'm thinking of CumulativeVolume, CumulativeDelta, number of trades, vwap level itself (each isolated within the selected period) to be highly useful.