Newbie here. If I use universe selection, can I subscribe the extended hours of the symbols?

More specifically, my goal is to day trade stocks. Need to update a list of symbols before market open, subscribe to their data and get their extended hour data only for analysis. If universe selection is not suitable for this purpose, how can I achieve what I want manually? By brutal force I might simply load the full list of symbols. But would that be too slow?

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