AMC does some funky stuff when they have these off-timing shows occasionally. Really, they're the only channel that does, they may be doing the thing where they push more ads right at the beginning of the hour (as the show extended a few minutes into the next hour), which is why they are extending the length slightly. It allows them to push more ad viewership for nielsen into a 5th quarter hour time slot.

This is highly unusual though, so they are kinda one-off weird exceptions.

Generally the most you'd see is 18 minutes in an hour, but even this is rare, 16 is more common for max ad time per hour, and its usually fairly spaced out evenly, give or take

1h9m would realistically be a about 22 minutes, at most of commercial time, that is if they do some awkward stuff with the extra 9 minutes, and go full steam on ads during the first hour

Just more explaining how it actually works for commercial blocks during airings