I second what @ChuckPa said. TV may be standardized, but there are many different rips (Web-DL, HDTV, BluRay, etc.). The cut-off point between different sources is not standardized.
Also, as I mentioned previously, your solution doesn’t scale well for multi-episode files that contain more than two episodes (Avatar being an example). If there were three or four episodes in one file, your proposed solution would cut the video at one-third, two-thirds, one-fourth, two-fourths, three-fourths? That’s entirely unnecessary.
From a consumer standpoint, I don’t care which episode of a multi-episode file I’m on. Using E01-02-03 as an example, I wouldn’t care if I’m on E01 or E02 or E03. I simply want Plex to sync the markers for all three episodes simultaneously so that they will stop and resume at the same time, no matter which one I choose.
If all three markers for E01, E02, and E03 are all in sync, then when I stop, I can continue at a later point by choosing any one of the episodes. All three episodes have the same marker, so it will simply resume where I left off previously.
Whether that’s E01 or E02 or E03, who cares? I wouldn’t watch E03 without having seen E02 or E02 without having seen E01. Just continue where I left off previously.
