Chrome/FF developer tools element navigation is slow #11

I've never seen this before so I'm not sure where the core issue is, but it seem to fit with this example as I created a preact app using preact-cli and react-toolbox so maybe you have some insight.

You can see the issue for yourself by navigation to my app. You don't have to login, just open developer tools, select the Element panel, and start expanding elements. You should notice a long lag with the responsiveness of the element panel.

I don't see this problem with the react-toolbox components page or the preact-compact-example page.

To attempt to isolate the issue I created a new app from preact-cli and only added the Snackbar example.

What I noticed was that importing components as shown seemed to be the problem.
In other words changing this:

import { Button, Snackbar } from 'react-toolbox'

to this

import { Button } from 'react-toolbox/lib/button'
import { Snackbar } from 'react-toolbox/lib/snackbar'

seemed to fix the problem.

However after following that pattern for every react-toolbox component I'm still seeing the issue. I did introduce changes at top level routes which obviously worked, but seemed to have diminishing returns and once I added the main app route back in it's back to being painfully slow.