Attempting to apply one of the new TC armor modifiers causes a client-side crash -- the ModCrooked and ModHammered canModify() methods are the issue, as they blindly cast the passed ItemStack to a ToolCore without confirming it is one first.

I'm unable to craft the Exo-Suit from Tinkers to test this. How did you manage to get hold of it?

You don't need an 'Exo-Suit', armor modifiers are applied to any of the Traveler's gear.