It is not possible to export MMS messages from the system on Vivo phones in China.

[ei0ch]

unknown error (code 0
SQLITE_OK): Unable to convert BLOB to string

Trying to turn off the following switches also had no effect:

Include BLOBs present in the MMS database table
Include binary MMS data

[tmo1]

https://github.com/tmo1/sms-ie#logcat