I went through Mods/0-DarknessFallsCore/Config/items.xml and built a list of all items which had a requirement name="ProgressionLevel" and property name="Extends" value="schematicMaster" and then compared those to the rows in Mods/0-DarknessFallsCore/Config/Localization.txt
Here's the items from that list which did not have a row in that Localization.txt:
armorIronSetSchematic
armorLeatherSetSchematic
armorSteelSetSchematic
cementMixerSchematic
chemistryStationSchematic
workbenchSchematic
(I did not do this by hand, I wrote a little script to do it.)
I hope this saves you some time.
I suppose I could also chase through and find the corresponding perk descriptions and build descriptions for each of those schematics that list the requirements. I would have to rely on google translate to help me with the other languages, and I do not know how bad that would turn out, but that's currently the biggest obstacle I can see. (Do you have friends who help you with translations?)