DB2 trace accounting records constraint filter by contents

My customer needs to gather SMF101 performance record to obtain stored procedures performance metrics. This is very important for them in order to deploy a DB2 stored procedures in production so they can effectively troubleshoot performance issues related to individual packages/stored procedures. To do so they need to activate accounting classes 7 and 8 but doing it may cause a too high performance impact, and mainly impact the volumes of their SMF data.

So they need to start this DB2 accounting trace but filtering for certain packages only. At the same time they want to keep the current level of trace info which is Trace ACCT (1,2,3) DEST(SMF).
After analyzing how to do it in PMR 40158,100,838 they found out that this is not possible because the filtering is done on a binary decision based on the state of the thread at the moment when the trace record is written and not based on the contents, so this yields undesired results when applying the filters with PKGPROG constraint and merging this trace with their current trace level. What they would like to achieve is the sum of these two trace outputs:
1 - Start trace ACCT (1,2,3,7,8) PKGPROG(SISXALF) DEST(SMF)
2 - Start Trace ACCT (1,2,3) DEST(SMF)
assuming that trace 1- filters on PKGPROG by contents.
According to the PMR this is not possible because of the way DB2 accounting traces are filtered, as they are not filtered by contents.
The answer received by L2:
"If they are looking to reduce content in the record, it will not work. If they are looking to screen out certain records entirely, the filtering works fine. As I have said before the package filters work exactly like all other filters. We look at the state of the thread at the time a record is being written--if it matches the specified filters, we write the record--if not, the record is skipped. These filters do not filter on content but rather it is a binary decision to write a record or not.
There is no current way to filter out certain packages from a 239 record as that would be a content filter."
The customer requests to have the constraints that can be specified in the constraints block of the TRACE command (all of them, not only the PKGPROG one) to work as filter by contents, to make sure that the filter captures only the records that match the constraint values.