Which @angular/* package(s) are relevant/related to the feature request?

compiler

Description

I have a set of routes that I prerender using the routesFile property, but for routes that are not specified in that file, the homepage flashes briefly. It would be nice if we could select a different page to show (like a generic loading page) or to configure it to not show a prerendered page at all.

Proposed solution

When a routesFile is specified, don't show a prerendered page for routes not in that file.

Alternatives considered

You could also override the default prerendered page that is displayed for routes not in the routesFile. Either by using some value in angular.json or just using the first (or last) entry in the routesFile as the default prerendered page.