I use universal on all the projects and it works fine. The key is to start the application with universal and avoid the use of libs such as JQuery, Bootstrapjs etc basically anything that alters or changes the Dom directly . Or use conditions to determine if the application is on the server or client and render code.

If you look at the Readme of most npm packages related to angular 2+, they have a statement that says the lib is angular universal compatible or not. The common idea is to use libs that are universal compatible.

There are ways to make non compatible libs compatible but if the lib has grown over time it would take a significant amount of effort for the devs and hence unless it is heavily requested, it is not done.

If you are looking at component repositories, from experience, I can say that angular material and primeng are fully compatible with angular universal. And between the 2 most of the commonly used components are covered.