Thanks very much for your reply!
If there are any casino affils out there who have used such a system, it’d be great to hear from you too.
It occurred to me that one way to do it would simply to have multiple affiliate IDs on a single affiliate program. Do any programs allow that? I guess it means more mess and hassle for them, so I can see why they wouldn’t, but it would allow an affiliate to better track different concurrent campaigns.