No, it is not compulsory to use mass-update. The docs describe this option. 

https://www.microfocus.com/documentation/extend-acucobol/103/extend-Interoperability-Suite/BKUSUSPROGS018.html

However, using this option means that the file is at risk from the time the first update is made until the time the file is closed. Should the machine die during this period, the file will almost certainly be corrupt. To mitigate this issue, Vision writes enough information to disk to ensure that the file can be rebuilt using vutil.