You can still make refunds and partials.....yes. More important is.......
Sellers can not require any one to use Paypal......in fact if a buyer DOES use Paypal the payment goes to EBAY, then after ebay holds the funds until buyer is happy (or does not complain) ebay then transfers the funds, minus fees, to you specified bank account. If the buyer has ANY ISSUES OF ANY KIND ebay will hold the buyers payment and refund it weather you agree or not.
A bigger issue that started 1/1/2022 is the IRS 1099K reporting. IF you sell more than $599.99 in a calendar year you will be required to file a 1099K and report ALL income from sales AND postage as pure income. Even if you paid $40 for a kit and sell it for $20 you can not take a loss (unless you are a INC, LLC or sole proprietor with license and tax ID) This new law means you can not sell more than $12 a week or it will affect your income tax filing. This new law affects ALL PAYMENTS via 3rd party pass through systems. The boss asks you to stop and buy doughnuts for the office, it costs you $50 and when you get to work he refunds you via Venmo or Paypal. This now becomes INCOME even though it was your boss returning money you loaned him. EVERYONE needs to know this so they do not have a very expensive surprise in April 2023.
As a retired bank analyst I can give you the reasons behind this but that needs to be done offline and not here on Spotlight.