I cannot get blocks into the white cornerpieces like the wiki sais I should be able to do. Tried with Iron, Emerald and Redstone blocks. Using HEE v1.8.4. Forge 10.13.4.1558

Read the part of the wiki that says it's over a year out of date and none of it is relevant anymore. Use the in-game Compendium for information.

You should maybe remove all the pages from the wiki OR state on every page that the wiki is horribly outdated.

BTW, I read the new stuff about enchanting the machines, but I did not see any hints to wether the ingredients for the enchants were correct. I have used several stacks of end Powder and different stuff and have not been able to find a single ingredient yet. The compendium mentions that the correct ingredients should leave more end powder intact but so far I have not seen any reconizable pattern yet.

Can't, it's against the rules of wikia. Ingredients unlock gradually when you try enhancing with wrong ones, or you can unlock them with Knowledge Points and they will show up in the GUI.