Changing flow routers! Kadira to Ostrio!

After upgrading to the latest version of meteor, we see a white screen when loading the apps main page.

The meteor support team advised us to change from Kadira to Ostrio flow routers. But surprisingly all webpages other than the root domain are opening just fine.

This seems like a massive change in about 1500 lines within our route.js file. The syntax looks different in Ostrio and it doesn’t feel like a find and replace.

Is there is an automatic faster way to replace the flow router? Kindly advice.