What you say is a Berry paradox. To be consistent we fix a programming language before any such definitions. So you have to count all characters in the BB(k) subprogram. Hence the total program for “BB(k) plus 1” definitely will have more than k characters.
I don't think my example (for example, "BB(11111) + 1") demonstrates the Berry paradox. The original comment "the biggest non-infinity namable number in k characters" is the Berry paradox, which is what I was pointing out.