I tried setting up dual mining on Ethos for a client. I couldn't get it to work so I started looking into multi algorithm switching. I couldn't find anything that would work on Ethos so I created a package of my own. Here's a package I created to keep your rig mining the most profitable algorithm. Defaults uses Nicehash. If you find any issues or want to request features please submit an issue on GitHub.
https://github.com/ajpsp5/ethos-auto-minerIts does donate one hour a day of mining time (roughly $0.15/day) towards improvements and an ethos mobile app I'm working on. Anyway, I hope it helps.