Hi @NovanByworks While it woulde be nice to have the Auto Smooth modifier in the legacy modifer menu, I currently do not have time to implement it, but feel free to contribute a pull request.
Also, auto smooth as modifier will be added soon to the context right-click menu in Blender 4.2 anyways, which whould make it super fast to add, so I do not think its worth the time adding.
In the meanwhile I would use this add-on that I made that amoung many things adds a auto smooth operation to the right click context menu that works smilar to Blender 4.2 and 4.0.
Also, keep the discussion of the fork of modifier list here instead, to make it more clear that its not the offical add-on we are talking about.