It's quite a clever policy from the SSP (if they are to back UDI).What harm can it actually do? The last I checked they only have 1 councillor in the whole of Scotland! It may attract some of the socialist Yes/soft SNP supporters who don't want to vote SNP on the list, and aren't attracted to the Greens.
It's a long time til May, but I have a feeling that the SNP may well win another majority and the Greens won't make anything like the 10+ MSPs some polls had predicted.
We'll see I suppose.