JH> I have a small shell script setup to check whenever I think about it:

I made one real quick that will check for a new version and download it if there is a newer version.

You could easily modify this to send an e-mail or to even unrar it and do a "./install replace /mystic" to automatically install it.  You'd still need to keep an eye on the upgrade/whatsnew text though in case there are additional steps needed.

NEW_VERSION=$(wget -N http://mysticbbs.com/downloads/prealpha/mys112a47_l64.rar 2>&1 >/dev/null | grep -c "Saving to:*")

if [ "$NEW_VERSION" -eq 1 ] ; then
    echo "A new version of Mystic BBS is available"
    
    # Do whatever you want here
else
    echo "No new version found"
fi

... A social life? Where can I download that!?

--- Mystic BBS v1.12 A47 2021/08/08 (Windows/32)