Reconfiguring from the OBiTALK Web Portal won't do anything for you that direct configuration or restoring a backup won't do.
The backup file is a collection of setting values, not a binary image backup of the OBi contents. Consequently, it's unlikely a backup will contain any corrupted data (and if it did, you'd likely spot it looking at non-Default setting values). I've never used the OBiTALK Web Portal and have restored from backup files countless times without ever needing to start over.