Etherchannel load balancing is always from the host device's perspective, for egress.
If you had a routed port connected to a ISP routed port, any MAC based load balancing would normally always see the same src and dest MAC (and load balancing would not happen).
If you had a non-p2p network between your device and the ISP, with src mac, you should see some load balancing, assuming you had multiple devices on that network, but likelt most traffic would come from just one host (e.g. FQ and/or proxy), and your load balancing would likely be poor.
Generally, if device supports it, your best option is src and desc IP load balancing.