The old PayPal module allowed to disable subscriptions and to only allow PayPal for one-off payments.
I would like to see this feature in the new PayPal module as well so we can switch to the new module since we don't want to deal with PayPal subscriptions. We have credit cards for that.
WHMCS Team Clarification:
This idea relates to the module called "PayPal", which is distinct from the preceding module called "PayPal Basic". Both have now been superseded by the "PayPal Payments" module.
Featured Comment
In WHMCS v8.9 we implemented the latest integration method from PayPal in a new module called "PayPal Payments".
This module enables merchants to make on-demand charges to client's PayPal accounts and credit cards on-demand and for any amount. Thereby solving the technical limitations of PayPal Subscriptions which have caused the pain points you've expressed in this request.
PayPal Payments is now the recommended module for PayPal, and you can seamlessly migrate from the previous PayPal Basic and PayPal modules over to it. For more information, see: https://docs.whmcs.com/payments/payment-gateway-modules/paypal-payments/