[cormacrelf]

Yeah. Tens of millions sounds fine. And you don’t have to keep navigating the raw zip file, you just do it once. “All file offsets available in a single immutable in-memory hash map” is basically the dream scenario. I imagine if you were desperate you could pack more in by representing your file names efficiently in memory, a bit of path compression or a trie or whatever, but if it already works it already works.