MWan3 - Sticky Sessions - Only by Source IP

Coming from a Ubiquiti Edgerouter Lite, which wasn't hefty enough to support QoS on my load balanced connections, where I used sticky sessions set to track by [destination IP && destination port], which was typically enough to keep banking etc happy. I note that in mwan3, the only option is to enable / disable sticky sessions, and from what I read in the documentation, this is done by Source IP Only. The upshot of this means that hefty multi stream downloads over multiple dest IPs (think Steam etc) end up confined to a single connection. In addition, it seems to keep my non-HTTPs traffic on the same connection at the same time, by virtue of having an HTTPs session within the timeout period (which there almost certainly is at all times)

Is there any way to customise this to select what range of identifiers (Src IP, Src Port, Dst IP, Dst Port) on which to remain sticky?

I think that defining ipset in dnsmasq file and later using it in the mwan3 for steering traffic might help. This applies to dest ip or destination domain.