Moo, its not the pH that effects spawning of cichlids. Its the gH and TDS in your water. If you have a high TDS and a high gH you will have a low, if anything, hatch rate from most south american dwarves, discus, etc. pH has nothing to do with it, but generally a high pH also means hard water, but not always. A low pH has nothing to do with the breeding of these fish. You just want very soft water with a very low TDS, probably no more than a 100-150 ms. Even then, the only thing ticky about most of the apistos and trying to get them to spawn is actually triggering the spawn. Many of them require an environmental change to induce the spawn, usually a water change done with cooler water simulating the rainy seasons.
Fish, wild discus are just as, if not hardier than their captive bred relatives. I would probably argue that they are hardier, simply because they have been exposed to all kinds of things in the wild, and would not still be alive if they couldn't deal with them, that not always the case with domestics.
Yep, the almond leaves are like peat and other such things you just throw on into your filter....but what happens when they stop releasing their tannins? You won't know, and then you do a WC, and you get a pH swing, thats real stable.
Using anything to "adjust" your water to the conditions you think it should be, other than RO, is just completely stupid. None of the more successful, and reputable breeders use anything other than RO. One its unstable I don't care what it is it will be unstable, and two its expensive especially for the world's top breeders and their volumes, even on a hobbyist scale is expensive. So if you want to believe all this and that, go right a head, but adding this to your water will only change the pH, it will do nothing to remove TDS, or soften your water...why because its still going to be right there in your tank, it doesn't just magically dissapear.
On to the evolution theory here, well lets see fish, certain traits huh....well last time I checked we weren't always living in the areas of the world that we are today....golly gee we adapted, and Golly Gee, maybe those super touchy die if they don't get exactly what they do in the wild discus can too, and oh my, they do every day. Its really amazing how many of the people on this forum, think they know soooooo much about discus, but nearly everything they say contradicts what the people on a few other forums dedicated to discus, have to say about them, Including some of the world renouned breeders and wild importers, such as Alberto from Aquatechnics who just successfully spawned Heckles in captivity, how'd he do it, by not giving them a WC for a week......hmmm but they need more care cause they are from the wild....well that line of BS just went out the window didn't it fish, do a little bit of research from now on, its amazing how quickly those ideas ya got can be thrown out the window, but then again, if ONE site says its ok, then it must be true....right?
