Customize template options

Hey team. Currently, the only way I can specify a template is with a string: 

```
<ConvertKitForm
    template="mills"
    headingText="Sign up for the waitlist"
    formId={1}
  />
```

I may be missing something, but how would we go about customizing the template options? For example, say we want to disable the `powered_by` option? It does't look like there's a way