I don't have a definite answer on what the best practice is, but have wondered the same thing. In the past, I would return a Future. Now, I always return type-erased AnyPublisher. I find it keeps the interface more general, seems cleaner (standard) and, like you said, often it's easier to work. Besides, the type-erased Future returned as AnyPublisher is still going to finish after one output.

Don't have a solution, but I'm experiencing a similar thing with the same setup. Compiling the files seems ok, but other steps are getting stuck often.