[rotrex]

no, they both will evaporate about as fast as their vapour pressure at the present temperature and concentrations of already evaporated methanol or water respectively will dictate.
There is some influence on the overall evaporation rate due to some physiochemical effects like azeotropic effect, change in surface tension, evaporation vs. diffusion to the droplet surface as viscosity also changes nonlinearity with the mixing ratio etc, but for the big part, methanol will evaporate very fast leaving mostly water behind in the liquid state. Due to evaporative cooling, the cooler droplets of water will evaporate even slower.

If you experience residual knock, you may just add more flow to compensate for the losses into big drops. As long as your ignition copes, you can just add more.