"would like to bulk edit the payment notification address on our listings. "
In addition to changing your email address at eBay and PayPal, you need to
revise every listing with your new PayPal address. There is no other way. Otherwise, the payment will be sent to the old address, even if you have changed your preferences at eBay and PayPal. Basically, the selection in the listing page overrides the preferences.
Yes, it can be changed using Selling Manager.
First, on the active listings page, select a bunch (10 or 20), and click the edit link (near the top at right)
It opens a page: "Select listing information"
Select "Payment methods accepted
Payment methods (You'll be asked to decide which ones on the next page.) "
"Edit listings in bulk." at bottom
and "Continue"
Select "PayPal accepted" and change the window to read "Add to ALL"
Then "Continue"
A box will open on the next page showing your current PayPal email address and allowing you to enter the new email address.
Then "Continue"
Finally "Submit" the following page.
Done.
It is time consuming but it works.
Good Luck.