Loss of the ability to install mediawiki on a simple hosting platform.
Perhaps we could allow for a graceful fallback, so if MediaWiki is running in an environment where a server-side rendering service is not present, then component rendering happens on the client-side.
Potential real performance penalty (we're calling a nodejs service, which are not known for their stellar performance, via the network for every page view
Maybe there's a way to separate out the rendering needed for unauthenticated users or otherwise generic component displays, and to cache this output, then do per-user customization as part of the client-side render?
Hard dependency of the basic website functionality on a second service reduces the availability of the website by the cumulative downtimes of the SSR component and MediaWiki
We could perhaps timebox the amount of time available for the SSR to some acceptable threshold, so e.g. if the request to the SSR service is more than 200ms, abort the request and fall back to a client side render.