My thoughts exactly, sure it takes time to completely break down but it starts early and a small plant that has just been up potted doesn't need much at first. Besides I recycle my dirt so there already are nutrients in there from the last grow.Regarding 'cooking' the soil mix I am not sure that it needs to sit and rest for as long as some think. Probably only a week or two should be sufficient. Lately I have been letting the compost component sit for several weeks which seems to be long enough for the microbe colonies to start breaking down some of the organic material. Then when the soil is mixed the micro-organisms can start working on the amendments.
OP, Buying individual amendments seems way too complicated especially starting out, a blended organic fertilized will likely give better coverage of your plants needs compare to the few ingredients you are using. Your plants look fine.