  How rapidly a planet grows in mass and how far they may park from the host
star depend sensitively on two non-dimensional parameters: Stokes number St and
turbulent $\alpha$. Yet, these parameters remain highly uncertain being
difficult or impossible to measure directly. Here, we demonstrate how the
ringed disks can be leveraged to obtain St and $\alpha$ separately by
constructing a simple toy model that combines dust radial equation of motion
under aerodynamic drag and coupling to gas motion with the measured
distribution of dust masses in Class 0/I disks. Focusing on known systems with
well-resolved dust rings, we find that the range of St and $\alpha$ that are
consistent with the measured properties of the rings are small: $10^{-4}
\lesssim {\rm St} \lesssim 10^{-2}$ and $10^{-5} \lesssim \alpha \lesssim
10^{-3}$. These low St and $\alpha$ ensure the observed rings are stable
against clumping. Even in one marginal case where the formation of bound clumps
is possible, further mass growth by pebble accretion is inhibited. Furthermore,
the derived low $\alpha$ is consistent with the nearly inviscid regime where
Type I migration can be prematurely halted. Our analysis predicts minimal
planet population beyond $\sim$10s of au where we observe dust rings and
significantly more vigorous planet formation inside $\sim$10 AU, consistent
with current exo-giant statistics. We close with discussions on the
implications of our results on small planet statistics at large orbital
distances.
