A couple more comments on Boron relating to their linkage with ashless dispersants (ADs)...
When you're formulating an oil, you usually have a selection of ADs in your armoury to play with; high & low TBN, high & low molecular weight, cheap & expensive and seal friendly or unfriendly. Your job as an oil formulator is to figure out which single AD, or combination of ADs, fits what you're trying to do both for the specific technical job at hand and the greater strategic scheme of things.
As a very bare minimum, you might have just two ADs that you need to 'balance out'. The first might be a highly potent, cheap, high TBN AD that's great for all manner of things (sludge, cleanliness, etc). However these ADs are usually very aggressive to Nitrile seals causing them to crack. Your second AD might simply be the first AD that has been post-reactively 'capped'. This typically will make it less potent (so you need to add more), lower its TBN & make it more expensive. However the net pay-off is better seal compatibility.
You can cap an AD in several ways. One of the oldest ways is simply to react it with a bit of Boric Acid. There are no hard & fast rules as to how much you add but the idea is you add it 'just to take the edge off', so that you just zap the most aggressive nitrogen sites. If you use a borated AD, you automatically see Boron showing up in oil. However remember that you may very likely use a COMBINATION of capped & uncapped so the level of Boron you end up with will bounce around depending on which AddCo has formulated the oil.
But you don't have to use Boric Acid to cap as any organic acid does the same job. Glycolic Acid can be used to cap an AD. It's more expensive than Boric Acid but has the advantage that it 'invisible' (ie it doesn't show up on ICP). This can be a boon in constructing linked, globalised formulation hierarchies. Likewise, you can cap with Poly Iso-Butylene Succinic Anhydride (PIBSA), the acidic chemical intermediate used in the production of most ADs. This too is 'invisible' and means you don't have to buy in & store a separate capping agent. Personally I don't like PIBSA capping because it can be abused by formulators to give a highly misleading impression of how an oil will perform in the field.
So, in short, Boron derived from boronated ADs (and Detergents) is not inherently bad. It's usually there to get through seal tests and that's it. However it's not without it's downsides. All capping makes for a less efficient, more costly AD & you will need more of it to achieve a given target. More AD in any oil brings it's own set of issues of which higher Noack is probably the biggest.
To the person that asked about HDDO's all of the above applies but with a couple of caveats. HDDOs do tend to contain more AD than PCMOs for soot handing. However HDDO seal test requirements are often less severe than their PCMO equivalents (VW's PCMO tests were far harder to pass than MB's HDDO ones). Also HDDOs tend to make far greater use of Dispersant VIIs which tend to be far less aggressive to seals than conventional ADs.
Finally, on a different topic, I wouldn't say Mg Sulphonate is anymore abrasive than Ca Sulphonate. If there is an issue with detergent abrasiveness, it's probably due to some suppliers not filtering their products properly, leaving them noticeably hazy when ideally they should be clear & bright.
QSGB doesn't have over 400ppm FYI either
If Boron was IN FACT BAD I seriously doubt any oil company would use it. Above quote by YOU is YOUR OWN opinion
