Frankly in the particular case where you have cascading downloads of small files, HTTP/1 is so unbelievably bad at that compared to HTTP/2 (especially in cases where the user-agent throttles TCP connections, like the limits of ~6 in a browser) that the "overhead" argument isn't really relevant because it might imply they're roughly comparable in some way. They aren't, in my experience, it's more like "Does it work" versus "Does it not work." I'm talking like one-or-two orders of magnitude in performance difference, in practice, in my cases.
Server push wasn't ever going to help use cases like this because pushing those files doesn't actually work very well; only the client knows about the state of its own cache (i.e. the server will aggressively push things even when the client doesn't need them). I tried making it work in some cases very similar to the "recursively download based on import structure" problem, and it was always just a complete wash in practice.
103 Early Hints are a better solution for that class of problem where the server has some knowledge over the request/response pattern and the "structure" of the objects its serving for download. They're also easier to support and implement, anyway.
Server push wasn't ever going to help use cases like this because pushing those files doesn't actually work very well; only the client knows about the state of its own cache (i.e. the server will aggressively push things even when the client doesn't need them). I tried making it work in some cases very similar to the "recursively download based on import structure" problem, and it was always just a complete wash in practice.
103 Early Hints are a better solution for that class of problem where the server has some knowledge over the request/response pattern and the "structure" of the objects its serving for download. They're also easier to support and implement, anyway.