You can definitely have a nice planted tank even with a higher GH. A good majority of plants do prefer soft water (lower GH) and do enjoy lower pH's. Of course there are exceptions, but those plants can usually handle the conditions in our tanks given enough time. Time and stability seem to be able to make many impossibilities possible.
Macro nutrients (NPK) should have no problem being added to any hardness. Maybe there's some threshold, but I doubt we would run into any problems with our aquariums. Maybe someone smarter than I might know of a problem, but I just haven't read where a problem might exist.
Micro's are a different story. Often, hardness gets confused. There's dGH (water hardness) and dKH (carbonate hardness) and many assume or mistake dKH as water hardness. dKH is just a measure of carbonates and bicarbonates (Hydroxides) in the water that buffer our aquariums. In my dumb TL/DR explanation, "if dKH increases then pH increases. If dKH decreases then pH decreases." This is also said to be the alkalinity of water.
Back to Micro's. Fe (Iron) is one the important micro's and it must be chelated as Fe just doesn't dissolve in our water. There are several chelates but 3 are often seen in our hobby. EDTA, DPTA and Ferrous Gluconate are the main chelates you will see. If I remember correctly, Easy Green is EDTA chelated. Each of these chelates react at certain pH levels. I will post a chart explaining this towards the bottom. But what we want to know is the pH of our water. If you are using Easy Green, and have a higher pH, the Fe becomes unavailable to your plants. In return, this would cause a deficiency even with a large addition of fertilizer. You'll want to pick a fertilizer chelated for your tank environment. Using Ferrous Gluconate can be used as it's is available at almost any pH.
One last thing to consider. dGH is made up of Calcium and Magnesium. Some fertilizers include these elements, so be mindful. Both Ca and MG can be overdosed and cause problems.
If you do have a high pH, I would look for a NPK source, separate Fe, Ferrous Gluconate and a Micro Mix.