I don’t know if it applies, but I don’t think reducing the file size is going to save you more that a millisecond or 4. ACF is using file_get_contents(). I seriously doubt that the size of the file is going to matter much to this function since it’s all happening on the server. According to https://www.raditha.com/wiki/Readfile_vs_include/ it only takes .00564 seconds to read a 1MB file and only .00152 seconds to read a 32KB file.
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