Pointless Cross-Class is still Pointless. BLM have low DEX in the first place, and increasing it by 15% isn't going to have any meaningful effect on block rate. Manawall is much better should you take aggro

And lol at using it for the Accuracy...if you don't meet accuracy reqs you shouldn't be doing Coil, and will still be missing all other times if you use this

Honestly, I think Hawk's Eye is an even worse cross-class than Surecast...