TRP Hylex RS replacement pad alternatives?

I like the Hylex RS brakes a lot, but I think the pads could be better. For the life of me, I can't figure out which replacement pads made by other manufacturers are compatible with these brakes. I know there are some, but the internets are being unhelpful. Anybody out there happen to know this?

For reference, the stock pads are these: https://trpcycling.com/product/hylex-rs-flat-mount-sintered-metallic-pads/

stu wrote:According to Swissstop, Hylex uses their 15C or 15E, a common size:
https://www.swissstop.com/brakepads/discbrakes/disc15/disce/

I've been more than happy with the 15E pads on HY/RD brakes.

Jumbo wrote:Now I wonder something. Swisstop lists them as fitting the Hylex not the Hylex RS. Do they take the same pads? Swisstop says that the 15E fits the Spyre. I had my Spyre pads out (have Spyres on another bike) and they're definitely bigger than the Hylex RS pads.

Volsung wrote:How were the stock Hylex pads?  The stock Spyres are notoriously average and lead to a lot of people giving up on the brakes early.