flushSync and Suspense

[vezaynk]

When I navigate with flushSync, I expect

1. the url to be updated immediately
2. any suspense boundaries that get triggered, should display their fallback states while loading

I generally see the second point as expected, but the url does not always update immediately. In particular, it seems like slow, aync loaders can negate flushSync. However, I'd like have a way to force the navigation and make the pages that aren't ready display their fallback states.