order_total modules update total but this update is not available to payment modules

[gernot]

Hello,
I am hoping someone can clarify how order_total and payment modules are supposed to work with the $order global.
I am running ZC v2.1.0, and noticed that although the order_total modules update order->info['total'] in the first part of the checkout, this updated information does not appear to be available to the payment modules later in the checkout.
Instead, different payment modules appear to be either redoing the order_total calculations entirely (paypalwpp for example), others seem to selectively add certain order_total components (e.g., stripe module considers low order fee).