No. Pyrocat is an acutance developer. The "grain masking" effect of the dye mask with staining developers can make the negatives print slightly less grainy than with a non-staining acutance developer, but you don't get fine grain. For fine grain you stick with a solvent developer like D-76, XTOL etc etc. Even Sandy King has said this.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh