Has anyone booked a Star Alliance award to Tahiti (PPT) using Mexicana miles? Please tell me if what I want to do is feasible...

United Star Alliance awards from N. America to PPT are 80/120/150 and United does not accept Membership Rewards point transfers.

Mexicana Star Alliance awards from N. America to PPT are 70/100/130 and Mexicana does accept Membership Rewards point transfers.

Has anyone tried to book a flight from N. America to PPT using Mexicana miles? I am hesitant to transfer a bunch of miles to Mexicana (as I need to leave from CLT and the Mexicana rep couldn't get me out of CLT.. whereas the United Mileage Plus rep has no problems finding flights out of CLT-LAX-PPT)