About the default URL
Thank you to have simplified the development of Angular 19 projects with Visual Studio 2022 with this project type. Just a remark : it is a loss of time to propose https://127.0.0.1 as a default URL for the development output, as Firefox considers this as a security risk, and does not display the results without the user accepting the risk first. The address https://localhost does not have this problem. Proposing both can also be a solution.
A question also : is it deliberate that after the first execution the server no more waits for clients calls, and we have to call npm start manually?
that's all standard development on windows with the local web server and the way it worked, when you first run a VS solution over 127.0.0.1 - it should ask the first time to save the permission from then on you should be good.. if you don't save the first time, it will asked every time. Not sure of your second question.