'The real issue for me was eBay changing all my existing listings to simple delivery and buyer pays without telling me they had done so.' 

Yes - the interference with existing listings has made the whole SD 'roll out' even more exasperating. If eBay hadn't been so indecently hasty to get SD underway, they could have spared us all this extra confusion - not to mention valuable time wasted, having to keep checking to see if changes have been made behind your back... 😠

Applying SD to new listings would have been much easier, with the opportunity to make sure the correct settings/courier options etc were all ok before going ahead. But no, it had to be 'chip-chop, shove everything over to SD, and never mind the problems it will cause...' 🤖