imho its incorrect arbitrary to set the static time periods for trading one should set the range, for example 5-130 min within that range each and every time when trend appears the time frame should be chosen by the method at this particular moment, and while the trend develops the time frame will have to be adjusted by the method (often there are multiple trends, often in different directions, and on different time frames) time-frames, as many other components, of the method should be dynamical, since in reality its kind of as focusing camera on the subject time frame should be function of the trend, not the otherwise so the same method may choose to use 15 min , next time 12 min, next time 18 min etc we r in business of timing, and choosing correct time frames for each trend while its develops is essential
so the "need" i was referring to is not imho how to determine usefulness of 4h time frame the "need" is to develop a way to choose the correct time frame when it was determined that there is a trend and to keep changing it accordingly while trend develops ones in a while it may happen to be the 4 hours time-frame for those who trade that range of time
My favorite is Weekly, 1 Day, 2 Hour, 30 Minute, 10 Minute... Weekly charts give my trend following signal buy signals, and then I trade via 1 Day for my exit. When I make trades of my Daily chart, I'm position trading (holding the trading for a week to a month), and I use 2 Hour charts to know when I exit. When I use 2 hour charts, I swing trade, using 30 minute charts to tell me when to get out). And I day trade (my definition of day trades is 1 to 3 days), with 30 Minute Charts for entrance and ten minute charts for exits.
My daily routine as a swing trader is: 1) Check ES-4 hourly chart v.s. daily SPY chart at market open 2) The rest of my day will be focused on 2-hourly, 30-minute and 15-minute chart.
For my manual trading I use this. Albeit I have some code that filters same price out of the feed, meaning my chart only moves if price changes thus no flat spots.