German Brewing

I have read that reducing DO will hurt head retention, is it possible that some DO is needed for foam? I have many low 02 beers that have pretty much no head (including the helles per the paper). At this point they all have a fair amount of residual smb (have lowered dosage since), could the lack of oxidation be causing this?

Mine were the same way until I started adding 4-6% carafoam

Low oxygen mashing does hurt foam in some sense, because the polymerized malt phenolics formed via HSO are foam positive compounds. That said, there are ways to get the foam back and make it even better quality than it was before.

5% carafoam will help, but the biggest improvement I saw was adding a 10 minute 76c rest. So nowadays my mash is 15 minutes at 64c, 30 minutes at 72c, and 10 minutes at 76c. I have a directly heated recirculated system, so I spend a good 10 minutes stepping from 64c to 72c. Sauergut will also increase the quality (stickiness) of the foam, as will spunding and gentle, cold lagering.

Glycoproteins, according to Narziss.

In general, polyphenols are what we are trying to avoid creating/extracting.

Not my experience at all. Awesome head retention before LODO, and awesome head retention with SMB LODO, SMB + Brewtan LODO and SMB + AA + Brewtan LODO.
Where exactly is the reference that LODO hurts head retention?
This is extremely counterintuitive. I do not recall a single Helles in Munich with bad head retention and I am sure I consumed more than 1000 of them.

Head retention hasn't been an issue for my lodo batches, even the first which used 100mg/l smb. I will say the latest two batches using cold ferment (7c) have noticeably better foam.

To clarify, I don't think it's quite accurate to say that preventing oxidation hurts foam.

What instead seems to be the case is that hot side oxidative damage improves foam, while at the same time damaging flavor. Basically, the "good" flavor molecules - simple, low molecular weight phenols - get oxidized and then chain up to form polyphenolic compounds which have a worse flavor but act as foam positive molecules.

So HSO can in some sense make up for other process shortcomings foam-wise.

If you are brewing with a solid process all around, low o2 will not result in poor foam.