Simple delivery now mandatory even for low value items?

Has Ebay made more changes to Simple Delivery?

It's been a few months since I listed anything new but I've noticed that now even if I have something low value (<£5) I can't opt out of simple delivery. I thought that as long as it was less than £20 you could ship it however you wanted, has this changed again? Or is the option to choose a different carrier been hidden somewhere?