It seems that under normal circumstances the most stress boxes a character can have is 4 with additional boxes becoming consequences.

Given the scenario of a character with Superb Endurance and Supernatural Toughness, does that mean the character has 4 physical stress boxes, +1 mild consequence from the Superb, and either +2 mild or +1 moderate consequence from the Toughness?  Or would they have a full 8 physical stress boxes (4 from Endurance, 4 from Toughness) and 1 mild consequence (from Endurance)?