I was just thinking about this after reading few posts and I am wondering if I should do anything. When I removed the factory air breather, there was a vent line there. The installation sheet for SE heavy breather elite called to remove the vent lines. There is no other mention of them.

I see someone out there managed to modify the mounting brace, drilling holes and installing few fittings, then routing the vent lines somewhere.

Should I do that? I mean, I don’t want to drill holes in my setup but I almost feel that if this was necessary, wouldn’t H-D include it in their setup?

Anyone with same setup on their M8 without the venting of the air breather?

 

Your new breather has a "vent" too, just different than the stock breather's design.
On your new breather, the bolts that go into the heads are hollow, so to speak, with a hole in the tip of the bolt (as did your stock ones) and your new ones have a hole in the side of them near the heads or on the shoulder of the bolt (stock ones had a hole from end to end).That way the heads vent into the center of the two head bolts that hold the breather's backplate on. On your new breather it vents out of the bolts where it comes out of the holes near the head of those bolts (or on the "shoulders"), from there there's a passage in the backplate's casting that goes from the inside of those two mounting bolt holes and out on either side of the big hole in the center (throttle body hole) of the backplate... where any fumes, oil, or whatever that is coming out of the head's breather bolts, is sucked into the engine and "burned" per EPA requirements...

If you want to do a "bypass" you can, its not "necessary", but a lot of us do... probably gonna require a little drilling and tapping and stuff on that backplate though.
I don't run the style of breather you have, but they're all the same "design" so to speak, just carried out a few different ways. Next week I am changing to another style breather... and I already have my fittings, drill bits, and taps laying out lol

 

Well....****...what do ya know...H-D did think about it after all lol. Thanks for your reply! I will just leave it alone lol. I have zero desire to drill holes through this thing.