This is an update to the first draft, which saves about 500 frames by finding an earlier skip input for the first cutscene (skipping it entirely), and having Indy stay on the ground at the second ladder to tag Marion sooner.
Yeah, this game for some reason makes it annoying to skip the one FMV most people will get to see in this game, since the input to skip it seems to have specific windows that the game will accept it. One very interesting thing I found was that trying to skip the cutscene pauses the game, and here, Indy and Marion are standing at the game's usual spawn point, which is much further ahead than in a new save file. Unpausing the game here just immediately starts the cutscene and drops you where you're supposed to spawn at, anyways. However, this could be a theoretical time save in the making if there is a way to stop the game from forcing you back into the tutorial area.
EDIT: 500. 400 was a bit of an undersell, actually. Also, I found out that tagging your partner will skip the animation of you picking up a special item (journal page, red brick, artifact, etc.), which is useful immediately after this TAS, since it allows you to enter the story a few frames earlier.