if you know the maximum price you are willing to pay, why would you care about shill bidders? As Clint Eastwood once noted in Magnum Force: "A good man always knows his limitations" 😉
and do you really want fraudsters contacting people on your bidding list offering them fradulent Second Chance Offers, using your Ebay ID as a ruse? Sure, eventually it will be exposed as a ruse when the poor soul gets taken and complains to Ebay. But in the meantime, your good name has been run through the mud by a poor unsuspecting victim.
I agree with you there are pros and cons, and no perfect solution to the problem of either shill bidders or fake/fradulent Second Chance Offers. You just have to decide as a seller, which is more important to you, the lesser of two lesser solutions, so to speak.