Chal responded regarding the C0 correction term and said that it was one of the missing pieces that he hadn’t figured out, so it looks like the current value of 0.04 is simply semi-arbitrary and should be adjusted to meet certain criteria. Noting that the total concentration of the system is changing slightly over the course of the simulation, it may be possible to correct for this in the C0 term.
Tested 45 and 30 degree initial contact angles (eq. angle = 70), the 30 degree simulation. Based on how the initial conditions are created, the 30 degree angle particle is much wider at the base. Both seem to exhibit similar behavior overall (growing towards equilibrium size). I think I am going to adjust the C0 term to try and maintain a constant total concentration and then see if t works at multiple angles. (C0 = 0.03 is an improvement but not a fix currently at 30 degrees).
(Images of 30 and 45 degree initials contact angles [IC and @1,000,000 iterations])