Will proutil dbname -C truncate bi command reduce the size of the bi files that are of a fixed size?

Will proutil dbname -C truncate bi command reduce the size of the bi files that are of a fixed size?
Structure file has several bi extents that are each 2GB in size.  If I truncate the bi, will this reduce the size of the bi files?

If the bi files are of a fixed length, then the size of these files will not be reduced when the proutil dbname -C truncate bi command is ran.
The physical size of the files will remain their fixed size.  The number of active clusters however will be returned to the original 4 clusters of whatever size has been identified as the default or current bi cluster size. 

Example:  

If the database has 3 bi extents of 2GB in size which means the bi file is making use of 6 GB of disk space.
If the db has a default bi cluster size of 512KB.  When the proutil dbname -C truncate bi command is ran, the bi file will continue to consume 6 GB of physical disk space.
However 4 clusters will be available for use which would be 2 MB of actual space being used within the current bi file.

The prostrct remove command can be used to reduce the number of bi extents associated with a database.  See article:   How to reduce the number of bi extents? for additional information.
 

References to Other Documentation:
Progress Article(s):
 Considerations when upgrading from OpenEdge 11 to a later OpenEdge 11 version.