Devtools causes severe performance degradation with many routes in state

[Mando-C137]

Which project does this relate to?

Router

Describe the bug

When the TanStack Router devtools are rendered (not opened), renders and navigations become slow if the router state contains a large number of routes. This commonly occurs when prerendering or preloading many routes (e.g., for link prefetching (preload"="render" or router.preloadRoute).

In my case, with a significant number of routes in state, the application becomes nearly unusable during development.

Your Example Website or App

https://github.com/Mando-C137/TanstackFaster

Steps to Reproduce the Bug or Issue

1. Visit the page
2. Navigate the app without the devtools rendered
3. Render the Devtolls by clicking the Show Devtools-Button
4. Navigate the app with the Devtools rendered

Expected behavior

The devtools should remain performant regardless of router state size.

Screenshots or Videos

No response

Platform

• Router Version: 1.162.2 (latest)
• OS: Windows
• Browser: Chrome, Edge
• Bundler: vite
• Bundler Version: 7.3.1

Additional context

No response