When the stat glitch was first discovered, there wasn't much understanding of how it worked, and timing was changed to include character creation. This possibly made sense when the glitch was thought to be based on some sort of overflow, but after some research I have determined that it's pulling from debug mode statlines at random. You can see the full list of debug statlines in the following screenshot of the debug mode new game screen, and the list corresponds exactly to the possible statlines you can get from the glitch:

In light of this, I believe that timing should start when the runner hits "Begin", as it was initially. As it stands, including character creation in timing introduces a tedious degree amount of RNG-induced resets at the beginning of the run, for something that doesn't actually involve any sort of interesting or difficult execution. If this change is made I am willing to retime the existing runs to match the new timing.

The current timing rules are, "Timing starts on pressing begin after character creation and ends when the credits start playing." In previous versions of the game, credits started playing right when you hit "End" on the final dialogue sequence of the game, but with The Final Cut, there's a long animation that plays before going to credits. Since there's no player input after pressing end, I'd suggest that the timing rules should be, "Timing starts on pressing begin after character creation and ends on pressing end after the final dialogue sequence." None of the old runs would have to be retimed, since it's only a relevant difference on current versions of the game.