this a 2 part question.. so first lets tackle the wheel spacer issue.
By increasing the offset of the wheel you place more stress on the axle’s studs which is never a good thing. i've run them on much older rigs that where just for getting into the bush and i wanted to run bigger tires. I was also around 20 years old and had no money, but that's besides the point. another issue is by adding wheel spacers it's just another component that can fail, and because of that possibility the majority of people on here will say to stay away from them. and to be honest I'm one of those people, it's best to just not run them. besides you have a expensive truck and wheel spacers are like spacer lifts, just a cheap way of doing something the right way. but this is just my opinion, take it for what it's worth.
to answer your question as to why Camburg didn't disclose the need for additional spacing... well did you order them right from their site? 3rd party? I'm not trying to be an a$$, but i quickly went onto Camburg's site and under 1.5 UCAs it says this in bullet point at the bottom,
- Will not fit OEM stock wheels, use our 1.25″ uniball version
maybe you missed this part? 3rd party didn't have it listed? idk but it's on their site.
not sure if this is what you wanted to hear but hey, at least you noticed there was a problem and asked for advice. honestly i wouldn't get rid of 1k$ UCAs and spend another 700$ on smaller ones. you can probably find decent wheels for that price.