Diminshed and closed both holes finally but no remarkable difference in sound, maybe little louder at WOT, don't have side by side comparison. I see more effect while restrict H-section but I leave MPE as it is now.
Eisenmann has more space to add valve between mufflers but can't see purchase and test in near future.
Sound clip - eventuri plenum+intake (w/o lid, mic between plenum and panel sub assy dash), stock midpipe (H-mod, X-delete), MPE (slightly modified, 2nd mic location near battery)
https://drive.google.com/file/d/1rRF...usp=drive_link