I’m a bit curious as it sounds like these fuses are meant to be used in tandem with the less expensive but more "musical" Purple and Orange fuses. I can understand this, in a few components I found Purple to be absolutely tubby and midrange saturated. On the other hand, I have tried QSA fuses that were very high resolution and dynamics, but totally lacking in fullness, texture, and bass. I imagine these might be similar, pushing the envelope technically, but relying on other fuses to make the sound musical/listenable, and easy to overdo with more than one.
I’m less inclined to think of these as a cash grab than being stuck at a fork where they aren’t able to put all the attributes they want in a single fuse, but they can make an overpoweringly technical fuse specifically for upstream components.
As much as people complain, I’ve used 3k power cords that have an equivalent or lesser effect than an SR fuse. Unfortunately, I think QSA did realize this and cranked up their prices to closer match other power products.