"However, these lower fees are currently only available to the UK and some other countries (France, Spain, Ireland and Greece are countries that I checked, which get lower fees, but the US does not get lower fees)."
Thats a 4th. reason NOT to use PayPal checkout. How can PayPal be trusted not to increase rates in the future.
Stripe has lower rates than PayPal, and better integration - at least in my experience with WHMCS.
I can say from my own experience in the UK market, a better way to save money on PayPal commissions is NOT to use PayPal checkout.
A better way is to get a wise.com account which includes UK Bank account details, as a high percentage of people in the UK will pay to
the UK Bank account with zero commissions involved.
Secondly PayPal never kept their promise of the lower 1.2% rate. After I implemented PayPal checkout in WHMCS there was not 1 single
payment in 3 months where PayPal did not continue to charge the higher rate. After I inquired they clarified that in practice the lower rate
would only apply to guest checkout payments where card details were entered. If a person used their PayPal account with a card as the
payment source the lower rate would not apply.
Thirdly due to the shopping cart process being changed so that people got sent to PayPal before even seeing a choice of paying by Internet
Banking, or new customers filling in their details, the commissions I was paying to PayPal actually INCREASED, and I lost a percentage of new
customers / business.
Saturn got a reaction from Remitur in New PayPal Checkout - with lower fees in some countries