Baffle : effect on tune ?

[Two dogs]

Meanwhile in Stralya  

We are currently going through a police blitz on aftermarket pipes and road noise.
Due to a small minority in the community winging in the papers about motorcycles and their disparity
of noise output v car.
So I am pre empting the pull over and fine issued and the palaver of getting the bike tested .
This is a shame as we have just been granted legal status to lane split and the moron drivers here
only seem to look for a bike if they hear it.

I have a S2R1000 with open full system Arrows /DP Race ECU. It sounds amazing but is really really loud.
The only baffle I have found to fit without drilling through the end caps (not going to happen) I can
slip in between the mid pipe and beginning of the CF cans  cheap 4" short 50 mm from eBay , I have one left over from
my R6 track bike project and plan on ordering another.

What , if any will this effect the tune on my Monster by adding back pressure ?

Thanks

[brad black]

blue line in first two graphs.  for comparison only.  s2r1000 mapping is different to gt1000.