I love to play around in with large data sets in Microsoft excel, but I brute force things a bit.
TURNS OUT THERES A FIND AND REPLACE TOOL AT THE TOP OF THE PAGE
That’s in all caps so I don’t forget.
Also you can reference cells on a separate sheet with sheetname!A1
To see if text is present use =ISNUMBER(FIND(“text”,A1))
Find is case sensitive. search is not.
When writing a formula for conditional formatting be sure to reference the cell you have selected
OR Functions only use two alternatives so need to be nested for three or more