Yes, if you enable CPU ABI splits there will only be the lib for a specific architecture available in an apk.
You could load the lib from a remote server after install if you need to save space but if we are talking about saving 1-3 MB I'd definitely save myself the hassle and just pack the libs for all architectures in one apk file.
You could load the lib from a remote server after install if you need to save space but if we are talking about saving 1-3 MB I'd definitely save myself the hassle and just pack the libs for all architectures in one apk file.