There is not currently a way to override how specific form inputs are rendered. For custom form functionality it is necessary to override the entire form component. I have had requests for more atomic overrides but I am reluctant to go down that path because at a certain point it just makes more sense to use generators. The intended use case for LiveAdmin is a private, internal app with minimal customization required.
However, it is possible to achieve what you want by simply copying the existing form component, customizing only the desired functionality (in your case the array input), and then setting the customized version as an override in the app config: config :live_admin, components: [form: YourApp.CustomFormComponent] (assuming you want all array inputs to work the same way–it is also possible to config the override for specific schemas). That said, for obvious reasons I can’t guarantee an input constructed with a 3rd party lib will work out of the box with LiveAdmin’s changeset handling–it might be necessary to make other customizations–but I wouldn’t expect it would take much since arrays are not a big problem for HTML.
And yes, more documentation would be great. I’ll join the other OS maintainers in saying, PRs welcome! I’ll be a lot more motivated to concentrate on docs myself once I am ready to release 1.0.
