Ok so in the rules for any% it states that "Modifiers and modes are allowed besides those restricted in the main rules" however it does not state any disallowed modes. would using Sandbox or the "No Bosses" mode from the custom menu be allowed for a run or are they too unfair?

Thanks for your interest! So we decided on no Sandbox or Custom mode for any runs. Custom just has too many variables we would have to check and we'd hate to reject a run just because someone didn't show all their custom settings. Also, it was probably 2am when we created the rules for the speedrun so they were kinda fast and loose so we could just get the page up. We're currently refining the rules so be on the lookout!