The irreducible-snark defect-3 conjecture

Let $G$ be an irreducible snark, meaning a snark for which deleting any pair of distinct vertices produces a $3$-edge-colourable graph, and let defect denote colouring defect. Irreducible-snark defect-3 conjecture.

$$\operatorname{defect}(G)=3.$$

Irreducible snarks form a subfamily of critical snarks, so this is presented as a weaker consequence of the critical-snark conjectures. Its general status is open.