There's a reason why traditional leather firefighter boot designs are still popular with wildland firefighters...and why some hunters swear by more staid boot designs over modern, high-tech and synthetic designs as well.
Let's go over that a bit more.
Part and parcel to why it's harder to get custom work boots here in the USA is the demand for labor. You see, a pair of custom work boots require craftsmen of exceptional skill to construct them.
Lineman boots are made for people that regularly ascend ladders, power poles with climbing spires, and other structures on a daily basis. This imposes certain requirements.