React 18: Updates scheduled from useInsertionEffect

[eps1lon]

Following up on reactjs/react.dev#4486 (comment) (/cc @acdlite )

React version: 18.0.0-rc.3-next-1159ff619-20220324

Steps To Reproduce

1. schedule an update (e.g. setState) from within useInsertionEffect

Link to code example: https://codesandbox.io/s/naughty-bogdan-boghf6?file=/src/index.js

The current behavior

Update is applied and no warning is issued.

The expected behavior

According to https://github.com/reactjs/reactjs.org/pull/4486/files#diff-a1c8ec10dc40c86b4bbd55ad3f0126835bd45e9aa9e56c846a2e28ad6dd6acffR602 useInsertionEffect cannot schedule updates. But setState seems to "work". Maybe this is just incidental because it's the first render?

I got the impression that this should definitely cause a warning (not implemented) but I wonder if we also should consistently drop updates from useInsertionEffect?