Was using indexeddb considered? I've yet to see an easy to use library that allows you to store simple but large json in indexeddb, and then query against that. Useful for something as simple as an emoji picker which needs to store keywords or aliases.
i mean, you can store it in localstorage or wherever to save net transfer for repeated use, but i dont think it would be faster to use indexdb directly at runtime.
The memory efficiency you might get would be that you don't need to hold the whole dataset in memory while running the filter step though at the moment it looks like it assumes you're working with an array in memory (https://github.com/leeoniya/uFuzzy/blob/main/src/uFuzzy.js#L...). That said I suspect there distance between this and something that could search against a stream of data is pretty short.