Layout Clipping Masking

Here’s something curious I stubbled upon years ago but recently realised it was useful for creating a more complex clipping mask.

( Has this been posted about before? )

So, from an exploded vector rendered viewport I was able to extract the following group, but is it a ‘group’…?

For clarity I applied a stroke and turned off fill…

I can use this to create a clipping mask…

If I ‘explode’ this weird group and re-group it it loses it’s clipping mask abilities and it’s clearly become a ‘proper’ group…

I always struggle with creating ‘hollow’ elements, it’s as if the algorithm forbids creation of them.
(You would expect an offset of a drawn rectangle and setting the inner rect to no fill would get a donut)
You have three of those.
It’s broken.

I don’t want it fixed!