Dual national with different names applying BC

hi guys. one of my friend is applying to BC but he is dual national already. he holds an EU passport which he is gonna apply with and also holds a non EU citizenship but he never uses it. it s a kind of dead citizenship for him. he also has two different names on his two citizenship.

my question is that he is applying with EU passport under EU rights and gonna fill the form with that passport info. however does he have to say about his other nationality and other name on that nationality. . or is it gonna be ok if he only fills the form as an EU passport holder without mentioning other nationality as UK allows multiply nationality i was thinking that should not be a problem .
has anyone been in this and can give some advice.

Interesting.
I haven't come across such post here before but I dont think there can be any problem since he's applying as per EU citizenship and those rules.

Perhaps you are already answered in this thread?