Customizing Ballistae into Horses

I’m looking for a way to change a Ballista’s attack and to have it change your stats. I’ve tried editing through Class Editor, but it won’t actually change anything yet.
What I am trying to do is so when you ride a ballista, it increases your movement and deals melee damage instead. Then I can easily change the graphics so it is like a character turns into a cavalier and is limited to it to just the chapters I want.

You want this, I think:

This makes the mount/dismount command freely available. If you want it only for specific chapters, it should be trivially easy to add a check into it that makes the command only usable when a specific global flag is ON.

If you want this functionality lmk and I’ll add it for you.
Please confirm that you’re able to get the hack working and that you will be using it before asking me to add said feature.