Is the HIGH USED TRACK value for a database Area seen in a CA Datacom CXX report available in any Dynamic System Table (DST)?
DST table DIR_DATASET column TOTAL_TRACKS is not the same.

z/OS

There is no equivalent DST column as of yet although this may be provided in future.

The CXX HIGH USED TRACKS is the highest track that has been used to this point while DST DIR_DATASET TOTAL TRACKS is the full size of the data set.
The only time they will match is if the Datacom Area had been populated through to the final track.
 

As documented:

CXX report:
HIGH USED TRACK
The number of tracks which must be processed to ensure that all data is read during the execution of a physical backup or GETPS. It also specifies the minimum number of tracks which must be formatted by the next load, and the minimum "move to" data set size (after dynamic extend for an ONLINE_AREA_MOVE. NONE indicates that either the high used mark option is set to off or the area has not been reloaded since it was turned on.
https://docops.ca.com/ca-datacom/15-1/en/reference/dbutlty-reference/utility-function-summary/report-generate-reports/directory-cxx-reports

DIR_DATASET (DRZ):
TOTAL_TRACKS
INTEGER No This field may contain zeros for an area not initialized. Otherwise, it contains the number of tracks allocated and accepted by CA Datacom®/DB for use.
https://docops.ca.com/ca-datacom/15-1/en/reference/system-tables-reference/directory-cxx-related-tables/dir_dataset-drz