Regarding 5W-30, Amsoil AEL low saps had Noack 7,8% and HTHS 3,7 in gray label and now it is 10% what is MB229.51 max allowed.
Amsoil AFL 5W-40 mid saps also had Noack 7,4% in gray label and now it is 10% too but MB229.51 listed.
Approvals cost money so blenders use cheaper base stocks probably to keep current prices.
More and more examples like the above of Amsoil oils changes recently.