Let me explain my thinking more....
I do not have the
TN Visa yet. When I get a job offer and go to get the
TN Visa for a job in San Francisco, they will see that I have already been to San Francisco (And that I was there visiting my boyfriend). They do make notes on your passport file regarding the purpose of your precious trips. If the custom official processing my TN Visa brings these notes up and see I previously went to San Francisco to visit my partner, will they not get suspicious of me? Because of this I am concerned they will think I am not temporarily coming to work, but that I plan to stay/immigrate/ marry my partner in the future, which is a no-no on a TN Visa.
I'm not so concerned about the LA trips because I will be looking for a job in San Francisco. I'm also not concerned about my ability to get through customs to visit him in San Francisco. My only concern is how my previous travel history will look to a custom official processing a TN Visa for me. Mainly I am only worried about making a trip to San Francisco to visit him before getting a TN Visa processed.
What do you think?