That says I should be adding 30 mL of each of the GMB but everything I have read on here says wait about 2 weeks before adding nutes...
This is a common misunderstanding. Every calculator starts its schedule at the point the plants are no longer considered seedlings. But here's the fun part: not everyone agrees exactly when that is.
If you look carefully you'll see that they recommend the base nutes at 1mL/L for cuttings/seedlings, 2mL/L for small plants, and the full 4mL/L for mature plants. The chart/calculator starts when the plants are "mature" enough to enter the typical veg stage.
Regarding the advice to give your plants "no" nutrients, that's more a soil thing than a hydro thing. Soil almost always has enough nutes in it already to keep a seedling happy and adding more would be bad. But in hydroponics the only nutes are the ones you give them. So your seedlings or clones only have the energy they bring with them to start with, and you need very light doses of nutrients to let them grow past that point.
Calculator is made to guide you trough, but you need to make your own decisions as grower. There is no 100% correct way to success, it is way of trial and errors. GL
This is a key thing that many people don't seem to get. "I gave them what the bottle said to and they died! This stuff is crap!"
Instead, it's our responsibility as growers to give our plants what they need rather than just following instructions. The pH Perfect line is the closest thing I've seen or heard of to something you can just follow the directions on without thinking, but science isn't quite there yet. I'd say you can grow just about any strain at 75% nutrient strength without ever measuring a thing - if you're running RO water of course. But even so I wouldn't actually recommend it because some strains will want more or less than that, and environment plays a massive role in this as well.
The nute companies do their best to print instructions that can be followed, but there's no instructions that would be right for everyone, we have to do some of the work ourselves and tailor the diet to the needs of our plants.