@Enrico Parisi 
We have added pool size in the 2025.3 release of the new UI.  Check it out when you have time!

Thanks for checking out what we have done so far with the new screens and providing your comments.  We are working to improve the functionality that existing customers expect AND create a simpler experience.  We posted this article to describe what has changed and several different ways to engage so please continue to provide feedback there, particularly on the ways you think we can simplify.   https://community.intersystems.com/post/20251-modernizing-interoperability-user-experience
 

Hi Alexander -- For now, the new UI is not available with the minimal security instance.  We have logged this as an issue to address.