Just to be sure that your secrets are reasonably available, always.
(i) GitHub for high availability of the repo, (ii) Openssl, even it is not flawless, it is available everywhere and battle tested (iii) Bash is bash :)
Looking at the script, a double round with aes-256-cbc [0] is done, moreover the file is hidden among thousands of files.
Like others ciphers it is vulnerable at implementation level, that is a enough long key must be chosen. Maybe the script could be improved adding a passphrase check.