This would be a excellent option. Additionally, if within the linked charts you held the mouse pointer over any 4H candle, the same 4 hour period would be very slightly shaded in grey on the lower time frame/s (1H, 30M, 15M or 5M etc) chart. This allows for investigating price movements over multiple time frames all at the same moment. Would work up and down all time frames. This is already an active function in ProRealTime charts.

Range bar charts with unlimited range setting would be very helpful.