Yes, he said that the fixture in the insta that I linked replaced his older one. I'm not sure it's significantly more sophisticated than other fixtures I have seen. It's nice though. The blocks at the front are cut away for clearance. Otherwise they are just vee blocks.
The tubes are chainstays. They look to be something that is commercially available, but maybe he added some bend. The interesting thing to me is that they are mitered off-center. I'm not sure that was intentional to add a little more clearance. I assume they are for a bike with big tires. Some people use s-bend chainstays for road bikes, but these have more bend than would be required for that. These appear to be for an all-road or mountain bike.