No special risk, just like you mention the preferred routing direction will not be respected and will created some constraints for the STD cell router.
hi, if u chose only one metal for PG rings, that means you will lay at least 4, long, fat, wires whose direction is different from the preferred routing direction, and APR tools can lay no wire to cross them.
hi, if u chose only one metal for PG rings, that means you will lay at least 4, long, fat, wires whose direction is different from the preferred routing direction, and APR tools can lay no wire to cross them.