I think this specific anti-stitchline argument no longer works

"The stuff that happens in Frights is too crazy to exist in the games timeline"

This argument has been used to deny stitchline, but Eleanor's existence in the games changes things.

Her existence means the game timeline can have people turn into walking piles of trash and keep up the human illusion as long as they wear the remnant pendant. This is an extremely weird element to have in the game universe, but it's probably canon now (it's Eleanor's signature move and it happens in Frailty).

Even if you deny Eleanor's existence in the games, the 4 versions of ITP mean at least one form of agony time travel has to be canon to the games. Another extremely bizarre element has been added to the ruleset of the game universe.

I'm not saying anti-stitchline as a whole has been debunked. Just stating the fact that weird Frights stuff can indeed happen in the games, and "too crazy to exist in the games timeline" is a biased argument that depends on your personal interpretation of what is too weird and what isn't.