I have the same inquiry. I typically fly DL BOS-CVG to see family, with a smattering of vacation and business travel thrown in, but am going to Hong Kong on a 6-month work assignment and flying over on a business class CX/AA codeshare ticket which would allow me to pass the Platinum Challenge with one (free) flight. Even though I'll be flying around Asia for work for 6 months, comparable CX status seems just so hard to get that AA seems like a no-brainer, but am I missing any other opportunities to jump into OWE with another carrier and enjoy broader benefits (e.g., AA lounge access on domestic flights)? I haven't seen similar challenges to AA's PLT-- do they not exist?