I have a mod that changes how the spiders look so then it doesn't trigger my arachnophobia. Would this be considered cheating because its a mod? The arachnophobia setting in game is fine for some but for me still seeing the legs triggers my arachnophobia. Below is the mod I use to play the game without seeing actual spiders. It doesn't remove them just replaces the model.

Until mod support is natively supported in the game, allowing any mod at all is tricky. There's no way in-game to see what mods are in use, meaning verification of a modded run would require that the video proof include how you launch the game, as a way to see the modlist. And possibly even more? I've never been a moderator.

Is there any reason you can't use the built-in arachnophobia mode? It replaces the spider visually and auditorily, doesn't it?

It should show the spider as just a text that says spider with the arachnophobia built in checked off. Unfortunately at the moment we can't allow mods of any kind as it would be too difficult to determine tampering