Actually CRS are very sensative and do not tolerate fertz. And most breeders use RODI water exclusively when changing or topping off in their tanks. Have to agree with you though regarding High Light and High CO2 injection without fertz, thats a recipe for disaster.May I ask what inverts you're keeping that can't stand any fertilization? The byproduct of the nitrifying bacteria that processes food and animal wastes in the water is nitrates and phosphates which the plants consume. If you're using tap water with any reasonable hardness, it contains potassium and magnesium. If you use PMDD or the Estimative Index and fertilize the raw nutrients as many of us do, it's very low cost and we're merely adding more of what exists already in low quantities, only we do it to a higher and more consistent level. My tanks for instance, were high in natural phosphates when I set them up, which is actually bad if they're too high because that leads to major algae. I was dosing PMDD which doesn't include phosphates, and as my tanks matured, the plants began consuming all of it and their growth was limited by that. I've since switched to EI for my large tanks and in the less than 2 weeks since the change, I've noticed some pretty dramatic differences.
My tanks are (variously) home to Amano shrimp, red cherry shrimp, a bamboo shrimp, tiger shrimp, and assorted snails. I've also kept crystal shrimp and blueberry shrimp in the past, which I inadvertently had in tanks with fish that would hunt them.
There are many algae and snail treatments, and some fish medications that can be bad for your shrimp and/or snails. But I've never heard of fertilizers causing a problem. Especially if you are using high light and CO2, your plants are surviving on what little nutrients exist in the tank naturally. They would likely grow like crazy if you gave them a consistent source of nutrients. You may be prone to algae if one nutrient exists at a significantly higher ratio than it should relative to the others, or you may be effectively starving the algae out, which while generally the goal, is done in our methods when done properly.
I honestly don't know what plants would fit in the high light, high CO2, no fertilization category. I've heard of low-light, and/or low-tech plants for tanks without CO2. Maybe someone can correct me if I'm wrong. I am surprised you're able to grow HC, are you using ADA Aqua Soil?