Did you try trituration on its own? Or is it just that the seed crystals were added, and when that didn't work, you added fresh EA and then observed crystals? I didn't need to seed mine, it crystallized spontaneously as excess CA was removed from the goo. 

Definitely recommend getting a notebook and start recording everything, a package of labels to put on your jars is really helpful too. I wouldn't be able to keep track of anything I've got going on without it. If you're up to it, get a cheap indoor thermometer and record the temperature while you're doing the extraction and salting steps too.

It also might be much easier to control the amount of water/solvent you're using by weighing it instead of using the gradations on your jars, which are probably not very accurate. 1 gram of water is 1mL at room temperature. 1 gram of EA is approximately 0.9mL. I've been using mass for everything throughout just to keep things as repeatable as possible.

Between the cactus paste that produced goo and the ones that yielded crystals, were there any noticeable differences in the consistency of the paste? The one I had success with without first treating the solvent with a strong drying agent had a much firmer consistency than the one that gives me goo. I cannot replicate that consistency with the cactus that yields goo regardless of whether I'm on the dry or wet side of the recommended range, though reducing the amount of water used did solve my oiling out issue.

I suspect that mucilage might play an important role, since it is well known for its ability to hold onto water, and the quantity of it would make a big difference in the appearance of the paste. I'm wondering if the low yields are actually due to low potency, or something like this confounding the results.