Pick the low hanging Fruit
Most IDNers target certain languages and/or certain niches in those languages. Cherry picking may cause you step outside your comfort zone and go after names in other languages. When you go over your daily drop list ( IDNTools.net) check
names relating to names on the drop list. How do you check other names not on the drop list? Check to see if any names on the daily drops are included in a list on Wikipedia.org.
Today several Vietnamese provinces dropped. I was fortunate enough to catch a couple of them, I assume that not many drop catchers are after Vietnamese names and another obstacle is many Vietnamese keywords or provinces in this case are 2 words so the Google.com statistics maybe a little off(since both words get concatenated together) . Please note the Google.com.vn shouldn’t be off for Vietnamese names. So while searching for Vietnamese Provinces I came across a nice list. I copied and pasted it into Excel and then remove the space(ctr-h for find and replace) and then checked to see what was available. I only checked dot coms and provinces over 1 million. But these were currently available and free to register

Indeed there are some jewels available to register in Vietnamese for the contrarians. Could pay off big, but as always beware and ask for native speaker help before committing much $$$
I agree there are risks with Vietnamese names and I would highly recommend consulting a native speakers as well.
For the record my Vietnamese names get the least amount of attention (unsolicited inquiries) of all my languages groups.