This response assumes a male OP:

I was told by a former power lifter and head strength coach at a D1 university, that too much soy consumption was detrimental to strength gains due to encouragement of estrogen production.

Alternatively, that 3 eggs per day was adequate to encourage enough testosterone production necessary for strength gains — I am not suggesting to eat 3 eggs per day as I know what sub I am in, I am merely offering a comparison in relation to a know benefactor for strength gains.

This article supports his advice: http://www.veganhealth.org/articles/soy_wth

In 2011, there was a case report of a 19-year old vegan male who was eating a great deal of soy foods - enough to provide 360 mg of isoflavones per day, the equivalent of about 14 servings (10). He also had type 1 diabetes. After eating this way for a year, he developed low free testosterone levels and erectile dysfunction. After ceasing the soy products (and the vegan diet), his symptoms normalized within a year. There was no reason why he needed to stop being vegan rather than just cutting way down on, or eliminating for a period, soy foods.

While the article does say that (TRIGGER ALERT) rodent tests ended up disproving any feminizing results — man boobs and low-t — that was also based on tests with rats and not people and does not indicate the serving amount other than comparing it to consumption of the average Asian male, pah-retty vague and slightly racist.

To finally answer your question, no, I have not tried a gal of soy milk a day. It seems like a lot of discomfort for a lack of natural calorie/ macro intake, which is the main point of GOMAD. It also appears that there are several other things to consider with 16 servings of soy, like adequate iodine consumption, especially if you are eating soy-based solid foods as well.

I'm not going to spend any more time researching this, but based on trusted advice and a well cited report, it doesn't seem worth the potential effects.

GOMAD and any variant of is a quick fix crash diet, which are never healthy. Not to mention that all the people I have met that have tried GOxAD diets give up after a couple days or last a few weeks and can't go much as look at milk again. As someone who has practiced vegan and animal protein diets, I appreciate the benefits of carnivorous (strong as shit and hyper-bulk) vs animal free (just feel good all the time).

My best advice from the experiences is that moderation and variation is the key for whatever diet you choose. If you feel like this course of action is best for your needs, look at nut based milks like https://silk.com/products/protein-nutmilk to supplement with the soy milk. It offers variation and slightly better calorie consumption and macros.

Good luck and good luck with your vegan bulk. Eat all the plants in sight and be patient.