DSFS takes 2 minutes to release ENQ on dataset member

Problem:
We are starting to use DSFS. When I open a member in DSFS, I can see there is an enqueue of DSFS on the member. But when closing the file, it takes another 2 minutes before the enqueue is lifted.

We tried to change the following values in the IDFFSPRM member of our parmlib:
PDS_ENQ_DURATION=3
PDS_INTERVAL=3    

After restarting DSFS, it looks like the settings are in effect. But nothing changed about the enqueue time. It's still taking 2 minutes to release.

Secondly, I made a script that makes copies of some members to another directory in USS, and for this copy-actions it creates an enqueue on those members. Is it really needed to have an enqueue on the member when just copying (not changing) the member?

Answer from IBM:
As you already found to control the time that enqueues are held on PDS and PDSE data sets, the administrator can use the PDS_ENQ_DURATION parameter. The default is 60 seconds. For PDS and PDSE members and PS data sets, the administrator can use the PS_DYN_DURATION parameter, which also defaults to 60 seconds.

However, this unfortunately does not work exactly as described. There is another component of this functionality that is involved here. There is a known design issue here where DSFS does not get an INACTIVATION from USS for the vnode associated with the data set in a timely manner. Under the current design, until DSFS gets this(which is around 1.5 - 2 minutes) we don't release the ENQ, regardless of what you specify for the timers.

I will suggest you to open an IBM Ideas, that's the way your request could be reviewed.