My personal record for Tamtara (level 16) unsynced on black mage was about 4 minutes and 15 seconds, so while it's possible to approach 10+ instances in an hour if you are doing something like light farming on a relic or anime, it's incredibly rare and something only done under very specific circumstances. I think A1S can be downed in about 2 minutes? Most 60 Ex mount farms also take about 3-4 minutes with a competent group. 50 Ex trials take a minute or less, hahaha.

Anyway, as others have said, XIV has no cap. The only reason to run that very easy content repeatedly is to farm for mostly unique / untradeable items so the gil farmers leave it alone.