I don't see the problem. Given an enormous WASM binary one could write a small bootstrap binary that fetches the binary and stores it in local cache. Future up

I don't see the problem. Given an enormous WASM binary one could write a small bootstrap binary that fetches the binary and stores it in local cache. Future updates to the mega-binary can be done with some kind of delta-diff mechanism. Now, let's say you rely on Qt in some manner. Well, likely the WASM package resides at some known URI and is subject to standard browser caching.