Monthly/Weekly - Open/Close vs High/Low

Looking for some opinions here from seasoned traders.

Do you guys prefer using O/C or H/L for creating supply and demand zones on monthly/weekly charts for 4H/D timeframe trading.

I was once told to use Monthly High/Low and weekly Open/Close.

Is that sound advice?

I don’t understand it, myself … so my [I]guess[/I] is that it isn’t, particularly. (I may be wrong, or have “missed something”.)

It seems to me that the key concept is that highs and lows are factual, objective and highly significant: they denote areas of support and resistance in the market; opens and closes, in principle, are more subjective and user-defined.