Only a handful benefit from them and more power to them if they choose to use armor, but given the lack of more than a slightly better set of armor the energy IMO would be better spent elsewhere.

Realistically cuendillar armor won't give much advantage over regular steel unless weapons are also being made of cuendillar (also a better use of resource IMO). Cuendillar armor won't keep you alive from an OP attack, won't help you against a canon shot and won't prevent a better warrior from chopping your head off. It's not like it's some "magic" armor ... It's just made from a superior material, advantage yes, but is it going to make a world of difference on a mass scale ... Very doubtful. Armor is armor.

If they are going to mass produce things from cuendillar there are more effective ways to put the resource to use. With canons in place city walls are far more vulnerable than in the past. With cuendillar walls canons are useless in a siege ... Not that Traveling doesn't make walls irrelevant, but then using cuendillar for any of these purposes seems silly since it's also impossible to adapt something once it's made.