Using a previous version of battleye to host a dayz server?

Using a really old version of battleye as a method of a server side hacking should be possible, right?

It cannot unfortunately. Battleye automatically updates to the latest one no matter what server you go on. The only way around that is hosting a server and turning off battleye. Hope I helped.

How about this little scenario, simplest one in the book, I've used it multiple times and it has numerous applications. You download an old version of battleye, put it where your normal one should be, and then set it to "read only". This will not allow battleye to overwrite any files inside. If you host a server, clients can connect and use a hack that is not detected on that version. If you paid to connect to the hive, then you have a server that can be hacked on easily.