Extract or tea or extract tea, typically these are all geared toward cultivating microbes, not delivering macro nutrients…

The GSR product you mentioned says it’s a bio stimulant that helps dissolve calcium carbonate in your soil. Seems like you should use it if you have a good reservoir of calcium carbonate in your soil, and its not available (because your soil is oxidized/over-tilled and/or high pH).

I’ve heard John say many times that bio coat gold is the most effective product for the price…it should always be used. However, that product is for getting seeds/seedlings off to a robust start. A healthy seedling can, however do a lot to make nutrients available later.

From everything I’ve read so far in your post, it’s not really clear if you have a deficiency of calcium in your soil, or you have a deficiency in available calcium. The difference is Important. Neither biocoat gold nor GSR is going to increase the quantity of calcium in your soil (or rather, they will only increase it by a trace amount).