While it doesn't directly address the question, it's worth mentioning that the accident that took the life of the then US Commerce Secretary, Ron Brown, took place on a twin locator approach into Dubrovnik.
The accident aircraft, a USAF CT-43 (B737), had only one ADF, but flew the approach anyway, apparently in violation of at least Air Force regs. A charting error was probably the most important factor in the accident, but the lack of navigational precision close to the MAP locator was also key in this CFIT tragedy.