I noticed that the current WR has weapons that is unlocked later in the game. I personally think that would be considered NG+ (since you have the weapons in the beginning of the run).
Any% would be started out with a clean file, restarting the story mode using the 'New Story' option. Timing would be the same.
NG+ would have all of the weapons, and can use the 'Rewind Story' option in the mission select screen.

Anyways thanks for reading this!

But what about alterations unlocked while playing the new game? My run was clearly started as a "new campaign" and not "rewind", yet it's considered an NG+ run because of alterations in the very beginning, with the timer still off. Kind of confusing - perhaps you should rename categories to "default loadouts" and "altered loadouts"?

Considering that he started the run using the New Story, and the timer does not offically start until the fire cutscene starts. I would consider that would a Any% run

Hey I saw the time and I'm not 100% sure but back when this game originally came out about 3 weeks after it came out if memory serves me right I did some glitch at the beginning of one of the levels and I fell out of world and completed the mission automatically I couldn't tell you what mission cause it was so long ago I just wanted to put this out there for glitch hunters I think it was after the 1st patch.

Most likely was old wounds as there was many, many glitches with the horse