'aural'!!!!!!!!
You were lucky. When I did my BCAR exams I had a 'oral' exams. That meant I had to do the talking. I presume an 'aural' exam involves a lot of listening.
Prior to converting to Pt66 I had UK BCAR A,C,X (elec, Inst, AP), R,R.
Now holding a full B1 B2, not getting double pay but getting more than my colleagues with either. I think that as long as an individual knows his knowledge boundaries and skills, I can't see what is wrong with holding both.
Nobody knows everything!!!