I would not know how to implement your idea to integrate intraday data into the spreadsheet System.
However I do have some thoughts to trying to avoid the Jan 20 surprise you raised:
You mentioned in an earlier post about using the System in conjunction with your other system. I think that is a good idea and makes a lot of sense.
I would use the System as a Primary or Confirming indicator along with some other TA analysis or "system".
For example, using RSI(14), ULT daily indicators would have given warnings around Jan 11-12 and the TRINQ EMA 5 signal (recently shared in an earlier post) seems to have given sell signals on Jan 12 and 19. Perhaps even using Support/Resistance lines could help.
The above techniques could be used by people who can't or don't want to watch intraday data but rather make their trading decisions at end-of-day or before next day open.