It's a hassle but you could lookup the ASN('s) of Netflix
I like "Weighted Fair Queuing" + "FQ CoDel" for anything as such: since I'm not able to differentiate traffic at Layer 7, at least I force the traffic to be weighted and fairly shared among internal clients, as well as different services for the same client.The most you can do is to give a higher priority in shaper to clients you use for streaming (even if for cloud bkp too), than to those clients that don't stream. Meaning, that weight 50 bulk 80/ 443 you mentioned should be further split to weight 66 based on streaming clients' IP addresses, and weight 33 for non-streaming. Maybe you will still have cloud bkp & streaming "fights", but only on those devices that do both streaming and cloud backups, and only when they do it in the same time. This cases, the weighted fair queuing should really help.
Thanks for the great input! I just realized I may have misunderstood the "Weight" value. I thought this was a priority of the traffic (i.e. higher weighted traffic has higher priority than lower weighted queues). Is it actually a percentage of the allocated bandwidth within a pipe?