How to use clGreen in Phoenixminer?

I have latest HiveOS beta and Phoenixminer 5.1c. I tried with stock 19.30 driver for my AMD 5700 cards and with latest suported 20.20. But everytime I add the

-clGreen 1

line to Phoenixminer it says

"The option -clGreen 1 is ignored for GPU0 "
"The option -clGreen 1 is ignored for GPU1 "
and so on…

So how can I test this kernel?