"Hold HBD to spend" is the dumb part of the spendhbd initiative.
We have tech that can instantly calculate conversions. Up-to-date payment systems need to offer this kind of service: The two parties agree a price in any given currency and the system settles in its native currency (HIVE for spendhbd, which is a Hive blockchain service).
HBD is a liability and those who refuse to hold HIVE for whatever reason have to pay premium for the self-inflicted friction damage. Of course, the market for self-inflicted damage harvesting is way greater than the market for an efficient service.
Once again, users do not care about the backend solution. Transfer HIVE.
RE: HBD and "dollars" in Latin Amercia - issues, treatment and concerns.