Hi @DTS Engineer , Thanks a lot for your reply. That is unfortunate, but maybe an enhancement request will provide a solution. I did also post the question on StackOverflow, and there is a way to make it work indeed. https://stackoverflow.com/questions/79128004/call-to-main-actor-isolated-instance-method-run-in-a-synchronous-non-isolated I think that is the same solution as you refer to when you talk about: very fragile assumptions that I won't recommend you make In practice, I do see this could work if you really have no other option, but sticking with Swift 5 seems more reliable indeed. I will create an enhancement request as you propose, thanks again for your help. Sander