im not exactly sure about this 'IMMED' options, because i don't have it enabled on our network. But as far as i can understand from its own help files.. 'you wouldn't have a chance, even a seconds to indentify for that nick.'
And also, if you Ghost/Release the same nickname, as soon as you used the immed nickname, the nick will turned to Guest again.
So, as recommend by the core services, its better to Disable the NickServ 'IMMED' options!