You could confiscate the domain so that both products have to compete from scratch, or go with a domain-splitting solution sort of like how the european regulat

You could confiscate the domain so that both products have to compete from scratch, or go with a domain-splitting solution sort of like how the european regulators' "Browser choice" resulted in a randomized list of browser options at first Windows boot. Not sure I'd argue either of those would work, but there are options.