Plotting a daily RSI on an hourly chart is not an issue. Screen shot below.
Notice that the value for the daily RSI = 71.07, this is the value for the previous day, the correct value for the daily RSI is 75.56. screen shot below:
At the start of a new day the value of the daily RSI on the hourly chart will update to that of close on the last day, in this case Monday morning will show the value for Friday close.
Is there any way to update the value of the daily at the end of the same trasing day or during live trading the EOD value may be updated on an hourly chart.