Are you using the CGM as a fertilizer or pre emergent?

that sounds like a pretty heavy dosage either way. I think the recommendation for pre emergent is around 20 lbs per 1000 sq ft. As a fertilizer, you could probably go a little lower. If I remember correctly, CGM is about 9% N, so using a single bag on your lawn would be providing 1.5 lbs of actual N per 1000 sq ft.

The soy meal and feathers recommended rate seems a little low, since that would be giving you about .8 lb of N per 1000 sq ft. And the part of that that is from feathers will be VERY slow release. I'd probably use 2 of those bags, for 1 1/3 lbs of N per 1000 sq ft.

If I remembered the N% of CGM correctly, the CGM is a better deal.

That seems like a really low price on the CGM. Is it Corn Gluten Meal or Corn Meal?

Too much of a good thing can be as unhealthy as the wrong product. What was the time period over which you applied the CGM? If all in one application then your nose should have told you something was wrong. The meal and feathers rate seems ok since it works out to 20#/k. Three or four times per year should work just fine. I'm skeptical of a NPK rating on a grain based product. It is about the protein and organic material added to the soil.

Is this CGM you've been getting from a feed store? The price seems to suggest it is. If so it isn't exactly the same thing as CGM hydroslate which is specifically sold and labeled as a pre-m.

The feed store stuff is almost always much much lower in nitrogen. I think the protein content is around 15%. And while the jury is out I haven't read any definitive studies suggesting that regular CGM feed is an effective as CGM hydroslate.

Your turf grass needs 2 pounds of Nitrogen per 1,000 square feet annually to grow quite well, applying more than that simply results in the excess flowing out of the soil into the ground water as a pollutant, even an organic product will do that. To determine how much N is being spread and the cost per 1,000 square feet multiply the percentage of N the manufacturer says is there by the weight of the bag and divide by the number of 1,000 square feet it covers to get a cost comparison. For example a 40 pound bag has 6 percent N so 40 x .06 equals 2.4 pounds of N and this bag is to be spread over 2,500 square feet so divide 2.4 by 2.5 and that equals 0.96 so you would be applying (if done properly) just under 1/2 the amount needed and if you mulch mow and leave the grass clippings to feed the lawn (1/2 the annual nutrient requirement) you have applied all the fertilizer needed for a good, healthy lawn.
Applying more than 1 pound per 1,000 square feet at any one time is a waste of your money since what is not used by the lawn will be washed out of your soil.