[until I can borrow someone's iOS device and actually record the process, this will have to do]

Thanks to CrazySpence a while back sharing a single picture and explaining the process to me, I found out how iOS users could install plugins on their devices without rooting them. It does require a PC with iTunes installed, still.

1) create a folder on your desktop, named "Plugins"
2) Extract plugins to this folder, as though it were the plugin folder for Vendetta Online
3) Connect your iOS device to your PC, and open iTunes
4) Under settings, find this screen:



5) Select Vendetta Online
6) Drag and drop the "Plugins" folder you created onto the iTunes window where it shows local files
7) [iirc] They are installed! safely disconnect your device and start VO.

If anyone can confirm this, or even better create a recording of this for others, that would be great, but I beleive thats all that is required.