I hate doing these kind of scientific nerdy stuff but I need coral blocks so bad. Thanks for making my suffering more tolerable. People like you make everything easier
I really recommend the "Easy Villager Trading" mod, you don't have to manually drag your emeralds into the item slot when trading anymore, you can just click the trade you want (or shift click to trade a whole stack). And also, though it might be a bit too cheaty for some people, Tweakeroo has an option to prevent villagers from locking their trades, so you don't have to build one of these void trading setups.