Soo I tried to add something to Ore Dictionary and I can say that its impossible.
I tried to create new Class that will read it but my class is deleted after recompile.
Adding registration to TestEnvironmentMod class removes it after recompile
and adding it to item class causing recompile errors
Now my question is that will there be option to create new entry for Ore Dictionary and have option in Block/Item mod element to assign it to existing entry?