I made an optimized sgminer for mining Xaya on AMD GPU. It's about 35% faster than nsgminer.
RX 580 at 650khs, Vega 56 at 1360khs. Check:
https://github.com/fancyIX/sgminer-phi2-branch/releases/tag/0.7.2-1

I worked hard on this for free. I posted this on Xaya discord channel but got banned. Strange and silly.