If learning to identify the poisonous ones seems potentially obsessive to you, other than to wish good luck upon you in your wild culinary adventures, I suggest that you consider learning to recognize plants by family. That way you can take advantage of the fact that many families of plants contain zero or very few poisonous or dangerous species. Look into Asteraceae, Malvaceae, Pinaceae, Fagaceae, Graminaceae, Rosaceae, and others. Two books I recommend for learning about this as a general rule (with plants, there is never such a thing as too much info, especially not when toxicity is a potential issue; one never knows until one knows; knowledge of poisonous plants is always better sooner than too late) are: Christopher Nyerges' Guide to Wild Foods and Useful Plants, and Botany in a Day: Thomas J. Elpel's Herbal Field Guide to Plant Families; although I happen to disagree with the idea that the Cactaceae is a safe family.

On the other hand, as a general rule, there are families to avoid. These might include: Solanaceae, Anacardiaceae, Apiaceae (Umbelliferaceae), and others.

I myself will never use the Universal Edibility Test to make up for not knowing for sure concerning edibility, but if you think you might, let me suggest that it be thought of as an adjunct to other knowledge. That is to say that even though you have not identified the plant in question positively to species, you have positively ruled out that it is not poisonous (it could be an oxalic [eat sparingly] or irritating species) and/or that it is not in a risky family. This and because there are edible plants and poisonous plants that look nearly identical, is why knowing ALL the poisonous plants in whatever area you are in is of great benefit.

The only time I personally would ever use the Universal Edibility Test, is when I already know the plant is edible, but I have never tried it before and I want to check for any allergic reaction I might have to it. Not that I am allergic to anything, but with new plants, one never knows.