Here are some offenders: examples/cc3000/shell.c, examples/nsh/nsh_main.c, examples/nxterm/nxterm_main.c, and examples/pty_test/pty_test.c. It is possible that for some of those, that represents the first call to nsh_consolemain(). But probably not.
To give other initialization options, I added nsh_consolechild() which is identical to nsh_consolemain() other than it omits all of the one-time initialization. Of course, you would not get the result that you wanted if nsh_consolechild() were called without nsh_consolemain().