How to prevent unnecessary mutation with useFieldArray?

[razb-viola]

This is the schema of my form:

z.object({
  ...somefields,
  business: z.object({
    type: z.string(),
    items: z.array(z.string()).optional()
  }).optional()
})

As you can see, business is optional. However, if you actually trying to fill it, you must provide a type, which is mandatory.
Now in order to allow items to be added, I am using the useFieldArray. like this:

const items = useFieldArray({name: 'business.items', control})

The problem is that by default it adds a business object to my form values with a blank array of items in it. Like this:

{
  business: {
    items: []
  }
}

Then when trying to send the form I get errors due to 'business.type' which is mandatory.
Could I tell some how to react hook form no to behave like so, or, the useFieldArray to be applied only based on certain conditions?

I may render this in a dedicated separate component. However when I unmount the component I should have to clean up the state and revert it to as it was before - manually.

[razb-viola]

Also problem with this, when you append a new row, you must provide some default value, otherwise typescript will yell on you.
For example: items.append({}) it tells me that I must add a property with name "foo" which is string. But... should I add default values for my customers? Should it be on their on decision, isn't it?