Is there a way to decouple the UI flow designer from the server?
Hi. Welcome to the forum.
Your question has been asked and answered many times.
However, In short, no. There is a larger issue at play (i.e. contrib nodes define their UI so 100% decoupling is not as straightforward as you may think).
Please search the forum for the numerous conversations on this subject for a better insight. (pretty sure there are several GitHub issue threads on this subject too)