Be very careful.  Even if they did make SD optional I  wouldn't sell anything on eBay now that I couldn't afford to just write off as a bad experience.  Looking at the feedback here on various threads and the thousands of 1* reviews on Trustpilot, it seems that the publicity around the BPF is attracting a lot of unscrupulous buyers (who didn't know about the MBG!).  Sellers are being ripped off left, right and centre.   For example, one woman sold a designer bag.  The buyer complained it was fake.   eBay immediately refunded the buyer and told the buyer to send it back.  The buyer did - but they sent her a fake bag in return, and her account is frozen because she 'sells fakes'.   She cannot get this resolved. 

It also seems that AI is making most of the decisions now about when and how to refund, and, possibly because of the very obvious BPF, the decision is being weighted more often than not in favour of the buyer with no recourse for appeal.   These kind of things are happening to sellers with many many years of successful selling and 100% feedback. Also, buyers are claiming refunds days or weeks after delivery, eBay just pay them out, and if you have no money in your eBay account - they have taken it directly out of sellers' bank accounts.  Sellers lose the money for the sale, and are often sent used and damaged items back. 

I don't want to sell anymore on eBay, as Simple Delivery is only one of the nightmares that sellers face on what is basically an unsafe platform for private sellers.