Hey! I'm one of the cofounders. Unfortunately I think you're right that this is due to our simulators being on iOS 26. We're actively working on supporting 27. Let me see if we can get that out now. I'd love to help you get unblocked; have you set up a Slack connect channel with us yet?
Update: we just added iOS 27 support. You can select it in the session settings dropdown. Feel free to try it out and let us know what you think!