as others have said, it's hella overpowered
it could maybe work with only allowing the +2 stats (note that arcane (+20 mana) is still within this however) but you're still looking at a +6% gain if it's only armor, which isn't super extreme for most stats but is still pretty significant for CSC
another alternative could be to have armor-specific reforges, so for example there could be "blessed" which has very minor boosts to damage and swing speed, or reuse "bulky" from melee weapons for significantly lowered speed but more defense