Not the OP, but I work on similar problems, albeit in a different setting (healthcare, millions+ of patients). The gist is that you have to bake experimental design into the deployment of your ML model, but in many cases a simple RCT or A/B test just won't cut it. This is largely because when you deploy a model, no matter how sophisticated or accurate, there's no guarantee that it'll actually move the needle in terms of the outcomes you care about—hence you need to run some kind of trial. At the same time, you want to maximize overall utility by not having to allocate more subjects to your control arm (or harmful, or resource-intensive and ineffective treatment arms) than you need to. This latter point is much more of a problem in medicine than it is in other settings, as you can imagine. These considerations point to adaptive designs that balance exploration/exploitation, e.g. those based on multi-armed bandits. Currently working on some cool (in my opinion) variations of MABs that incorporate domain-specific knowledge, so I could talk about this all day!