wavy flight plate
I have done a few dye jobs that used boiling water with mixed results. I do think that the color sets quicker, but you need to watch the temp closely. It is plastic and it will warp. I experimented with a shaving cream dye on a clear Prodigy disc where I laid out the shaving cream pattern on the underside of the flight plate and then floated it in near boiling water. The color looked awesome, but the flight plate warped horribly. It was basically one continuous wave all around the rim. The rim itself was fine, but the flight plate was badly warped and it is probably an illegal disc now, given how out of spec it is.
I think that the best thing to do is to be patient. When you add the dye, get a good boil to maximize the solubility of the dye and water, but then let it cool down some before the dyeing process. It takes more time, but also gives you more control of the depth of color and won't jack-up your plastic.