Is shikantaza meant to spontaneously relax you, unlike ch'an meditation?

Is shikantaza meant to spontaneously relax you, unlike ch'an meditation? I've never taken classes in the former, but the latter seems to *teach* you to relax -- and then follow the breath spontaneously. Is this about right? To stay alert, in zazen, I focus on the tip of my nose, as and when I need to. If my thoughts bother me, I mentally turn toward them (both literally and metaphorically). I believe that is still zazen? I don't have any other questions about how to meditate, anymore; though I'm unsure what enlightenment or jhana is.