On a simple test, it takes ~8s to connect to an already running flutter observatory via flutter attach. Though ~3s was from cleaning up the devfs and closing the process.

Log gist at https://gist.github.com/xster/5becc4937c2cef8d5e84660d0601abd1

There's a 2397ms apparently pure Dart part in the middle of the process too.

We should optimize.