Yes mate I'll often up the lime to make the gear more workable as much as anything when making it weaker.
If you make sure that an 8:1:1 ratio cures properly it'll be plenty hard enough to paint and still look great thirty years down the line.
I always use fibres in both coats with S&C and even then still put stress patches in, and that's even on dense blocks. Now I'm starting to use the Parex gear I'll always fully mesh as I can't put fibres in.