Just a follow up and have doubts that you really care, lol. But thought I would throw this out since I asked the husband how he did it:
Have no clue what he means by"
I used the phpseclib/mcrypt_compat shim:
composer require phpseclib/mcrypt_compat:*
Anyway, will use our old method of building software so can continue to support existing apps without completely redoing them for libsodium