With a Ryzen 1700@3400 16 threads in Ubuntu I get 0,35 g/s . Too low for this insane difficulty, but work.
Sadly i couldnt take any Grin, but i like the project, good luck.
you draw conclusions too fast, it depends on how much it would cost, with CPU you will not get much on any coin. in my rough estimation it will be on pair with other cpu minable coins if it will cost ~12$ or ~50k sat per coin. the estimation is based on first 12h of mining and can be totally inaccurate in the long run.