Code is very small, which is very good.
I have only few comments.

1.   StTagFilterMaker.
================
1.1   TString mTagFile; /// Tags input file name
       TFile *mFile;
This maker reads tag file itself. To avoid desinchronisation it searches in tag file by Run/Event.
Question: is it fast enough?
May be  itwould  is better to read tag file inside of StIOMaker, which reads all the files.

1.2 int mEventCounter; /// Number of events
It would be good to clarify. Number of which events? Accepted? Rejected or all?
I found that it is serial event counter. It is already exists in StMaker class.
GetIventNumber() do this job (Ivent not Event)

2. StMtdEvtFilterApplyMaker
=====================
Bool_t StMtdEvtFilterApplyMaker::SkipEvent()
{
...
   // Make shouldHaveReject and tpcSectors globally available.
  SetAttr("MtdShouldHaveRejectEvent",GetVal(1));
  SetAttr("TpcSectorsByMtd",GetVal(2));
...
}

multiple calls to SetAttr l;eads to memory leaks.
It should be used some other mechanism, or fix SetAttr, removing the same name attributes.

3. That is it.
Victor