What about something like this:
install(DefaultModule.default()) // DefaultPlaceManager, ParameterTokenFormatter /// but looks to have an default() in a DefaultModule
install(DefaultModule.builder().tokenFormatter(RouteTokenFormatter.class).build())  // DefaultPlaceManager, RouteTokenFormatter

I do not really know if this is a good idea because it makes a helper class more complex. On the other side things like default/error/unauthorized-Place could added to this Builder pattern.

// may be?
install(GwtpModule.builder().defaultPlace("/").notFoundPlace("/404").routeTokenFormatter().build());