How to conditionally disable client side

I have a server-side rendered app (with transition) and I have a 404 page that I've put in a lazy module (so I don't increase loaded Javascript size).

This is working fine, but there is some flickering when the client side takes over, which I think is due to the JS chunk loading after the main chunk has finished loading.

Given this page only contains static links and one routerLink, the client side is not needed at all and I'm wondering if there's a way to disable the client side on certain URLs

Edit: as suggested in the comments I tried to conditionally bootstrap the application. I can't use the URL as a condition because the server responds 404 on the non-existing URL (there is no redirect at this point). So the most appropriated thing to use is the TransferState which i successfully set up on server side and it generates some output just before the closing body tag.

Unfortunately I didn't find any way to properly instantiate TransferState in main.ts because it's supposed to be imported via BrowserTransferStateModule and I see no possible way to import an Angular module in the main.ts file.

I tried to instantiate it directly with the initTransferState function but it appears it's not designed to be used outside the module since i get an error :

ERROR in ./src/main.ts
Module not found: Error: Can't resolve '@angular/platform-browser/src/browser/transfer_state' in 'G:\Documents\Projets\Myapp\Sources\master\frontend\src'

Any idea other than doing some dirty deserialization?

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