Delay children mounting on Loading boxLoader type

[bvego]

Is your feature request related to a problem? Please describe.
When using the <Loader type="boxLoader" ...>... it attempts to mount the children. This is very annoying in the following use case if some of the data that the children need to access isn't available. E.G. data is null/undefined/an empty array...

<Loader loading={fetchingSomeDetails} type="boxLoader" text="Loading">
  <div>{detailsThatAreSupposedToBeFetched.someProperty}</div>
</Loading>

Describe the solution you'd like
Check the loading prop to calculate whether or not to mount the children if type="boxLoader" or maybe pass a prop that will do this functionality

Describe alternatives you've considered
For now we use the following to delay the content:

<Loader loading={fetchingSomeDetails} type="boxLoader" text="Loading">
  {detailsThatAreSupposedToBeFetched && (
    <div>{detailsThatAreSupposedToBeFetched.someProperty}</div>
  )
</Loading>

It would reduce some code if this was done by the component itself