No concern needed, tiley. Magnesium is part of a detergent molecule and calcium is as well (interchangeable roles) and calcium detergents are mostly superior to magnesium detergents. Boron can be part of a wide variety of additives, detergents, dispersants, or anti-wear additives. Most internet discussions have misleadingly named boron as an anti-wear alone and thus praise it for supposedly making up for reduced ZDDP levels in some oils. There's very little way to know what the boron is part of in any given oil, so don't be concerned about it. Having it is not fantastic and not having it is not bad.
This oil is loaded up in calcium detergents and ZDDP, with a very strong TBN. That is a great start and with Motul's high quality, I'm sure it's excellent, as some UOAs have shown already.