You can BLOCK in your eBay site preferences bidder who have had two or more UPI strikes in the last 12 months. Use it.
Perpetual non-payers will not be allowed to bid on or buy your merchandise.
You cannot block bidders with a low feedback score...only those with a minus one....that is impossible now, for buyers cannot get a negative, but was useful in the older times for the Nigerian Bid/bin bandits. A seller who got the normal..."please send to my (son, daughter, grandmother, uncle) for his (birthday, graduation, first communion) in Legos.." could pop the ID with the neg one, preventing the next 100 sellers from a similar fate with the bogus ID.
eBay likes these bidders. They are still here after almost 20 years. Go figure.