I always thought that if you cross two F1 siblings you get essentially random plants from the seeds and needed to cross back to stabilise the line.
I would think the seeds from breeding 2 "shitstorm" plants would result in essentially random plants with wildly varying characteristics.
To get homogeneous plants surely you would have to breed the F1 shitstorm with the F1 catdog, not from plants grown from seeds from shitstorm x shitstorm and catdog x catdog.
F1 still applies to my mind as seeds from F1 crosses (between siblings) don't breed true.
F1 x F1 when not siblings should (AFAIK) produce homogeneous offspring
We seem to have left the land of stable breeding lines and are now in the land of random lucky crosses in a lot of cases.
If everyone was breeding like this then the plant itself as we know it would most definitely be in trouble but luckily, we are not homogeneous in our breeding methods
Someone somewhere will be going to the effort of keeping stable breeding lines. They may save the day at some point in the future...