Tandems too far forward?

I've never had issues with too far forward. I run in the Western states, unsure if it's much of a thing here. I just don't know.
I prefer to have my tandems at around the 40 ft length in general. Never have cared for them being all the way forward. To me, the 40 foot length just seems like a good balance of maneuverability verse swing out.
Since I run CA alot, seldom get to have them any farther back if I wanted.
I also run heavy most of the time averaging between 75k and 78k gross. Anyway, tend to run tandems as far back as I can to have legal drives. Up to the 40 foot mark if I'm going to CA of course. If drives are still too heavy at the 40 foot mark, have to get the load reworked. So far it has only happened to me once.

 

Gee Dave, if I didn't know better, I'd say you don't like California much!

 

I honestly go by some sticker line the company shoves on the trailer. If it's above the middle of the tandems then I can't go further back. I often have it either over the rear wheel or all the way forward. Depending on load. I'm often running Maine to Wisconsin or Maine to Georgia no issue. Only bridge law company told me about was the one in Connecticut

 

Ok I have to ask, what’s CBA stand for? Center of back axle?