Looks like a good find!
I stopped using yellowstuff on track, because they would give up after only one hot lap (started vibrating as they overheated). Our cars are too heavy for these pads on track, but you may not feel this with floating calipers.
Just wanted to share that experience. Rear pads are obviously not as critical, and certainly not on the street. Then just be careful to mix with pads that have similar friction coefficient up front in order not to push the brake balance rear-wards. The yellowstuff should be grippier that average.