The only way to know for sure is to contact the embassy. I've heard of instances where people with American tourist visas had no issues transferring their visa into their travel document at the US embassy. But you would still need to apply the same way you apply for a new visa and let the officer know of your case when you're there. Good luck!Is it possible for someone to apply for a visa to visit country X using RTD while having a VALID visa for the same country X on their home country's passport?
Would the embassy/consulate reject the visa application for the said reason as he/she already has one on another passport?