Please add the ability to manually tweak/adjust intro markers. Certain shows have unique content in the intro for each episode (e.g. quote in the beginning of the Futurama intro sequence, icons depicting the major themes of the episode in Ozark… etc), so it would be nice if we had the option to manually adjust the auto analysed intro markers to, for example, skip less and show the ending bit of the intro. Plex at the end of the day is a platform for home server enthusiasts and tinkerers so this would be super useful 
There’s an existing feature suggestion asking for an option to manually add/edit the timestamps used for the skip intro feature
I suggest you comment/vote in that thread in order to avoid distracting/dispersing votes. I’ll therefore close this thread as a duplicate.
2021 clean-up: duplicate