If you’re filing from outside the U.S., they only process cases in Texas — it’s written right on the USCIS website. Even if you send it to Nebraska, they’ll just transfer it to Texas later. Basically, it doesn’t matter where the case ends up.
The employer’s address has nothing to do with it — if you file through consular processing (i.e., from abroad), the case goes to the Texas Service Center regardless of the state where the job will be. When I applied from Moscow — my employer was in New York — the case went to Texas. The address only changes if you already live in the United States; then, yes, it depends on your state of residence.
For consular filing it’s only Texas — I filed from St. Petersburg with an employer in New York; it was sent there. The work address doesn’t affect the processing center, that’s only for AOS within the states.
Oh, you won’t get confused here — if you file from abroad it’s always Texas; the employer’s state has nothing to do with it. When I did mine, the company was in New York but the petition still went to the Texas service center. On uscis.gov there’s the lockbox filing locations chart — it literally lists the location by filing type)