well i am afraid this is not true. the wallet partial payment is not working properly. where it should be calculating everything in the cart and any fees added, it only triggers if the products value are more than the wallet balance. unless you are only using default shipping of woocommerce, then it will include the shipping in the calculation and triggers partial payments . try it yourself. the partial payment should be triggered no matter what custom feess are added, so it should check order total not cart subtotal. please check and let us know,