I recommend T4 over T1 for a variety of reasons. Among them, T1 security sucks worse than most and the TSA folks there have resisted access for lounge visitors more than other terminals typically have. Putting aside whether they should or not, I don't think it is worth the fight.
Also, if it is the KE lounge I think the access hours are limited for Priority Pass and might not work for afternoon/evening anyways.