I tried adding the vanishing trait from ender io to a material and it didn't work. I know the syntax should be right as I was able to add the direct trait from looking through the source code. However after looking more carefully at the code I noticed something that could be causing the issue.

https://github.com/SleepyTrousers/EnderIO/blob/master/enderio-integration-tic/src/main/java/crazypants/enderio/integration/tic/traits/TraitTeleport.java

Line 30 has this after it sets up enderport which is "-" + variant and I'm assuming this messes with the naming somehow. Now I'm wondering is it possible to add this trait in currently or would you need to do something to get around this? Or am i doing something wrong by using enderport (and yes I did add a number after it unlike my earlier issue when my brain decided to go boom)

hmmmm yea I also had issues with many other traits but it was so long ago I forgot about stuff since I just left most traits untouched. I might go back and change it soonish because of balancing reasons in my pack and hopefully you'll be more available to help me out then.

The names for all the levels seem to be enderport-0, enderport-2, enderport-3, enderport-4. It's a bit confusing that different mods have different conventions for how the levels are handled. If you have a mod that can view the metadata of an item (such as crafttweaker) you can use it to see which traits the tool has in the trait tag and you can see the internal id of the traits.