There are two camps for racks:
Sturdy, heavy and rigidly coupled or lightweight and decoupled.
This one is far into the latter camp. Which one sounds best will probably depend upon the floor.
Importantly I wanted it to allow for plently of ventilation and this is how I solved it.
Yes, it's a power station. However it's not just some random power station.
It's the Bluetti EB3A and I tested many before I found this one and saw that it was the only one that worked for my needs. For virtually all of my listening the fan stays off and it provides my system with 2.5 hours of listening time.