When canceling a recurring donation via the Civi UI we see "Automatic cancellation is not supported for this payment processor. You or the contributor will need to manually cancel this recurring contribution using the payment processor website."
That's not accurate for Ingenico, Adyen, or new Dlocal recurrings - we can just cancel in Civi and they won't be charged any more.
Looks like we just need to create a cancelSubscription function on the class OR we can override the supportsCancelRecurring function. As a bonus we can make it actually cancel PayPal subscriptions and save Donor Relations some time searching in that UI.
protected function supportsCancelRecurring() {
return method_exists(CRM_Utils_System::getClassName($this), 'cancelSubscription');
}