Blacksmith & Engineering respecializing help!Follow

It's said that most old-world plans have been removed its specialization requirement.
However, I find that there are still 2 plans do require specialization.
"Fiery Plate Gauntlets" requires Armorsmith.
"Dark Iron Pulverizer" requires Weaponsmith.
Now I am an Armorsmith.
My question is what plans i would forget if I paid 100g for respecializing.
Many said all old plans would be retained, which i doubt.

How about "Fiery Plate Gauntlets"?
How about Trained old-world armor plans such as "Truesilver Gauntlets"?
How about Trained tbc armor plans such as "Bulwark of Kings"?


In fact, I am also a Gnome-Engineer.I face the similar problem as Blacksmith.
Engineering is more complex.
Some schematics are taught by gnome-trainer, some old, some new.
Some boe schematics require Gnome-Engineering to learn.
Lil' Smoky schematic is a reward from Membership Card.
Which schematics would i forget if i swith from Gnome to Goblin?

Respecializing cost much, and I am hesitate.


Any hardcores help me ?