I’m aware of the problem, and right now, we need to deal with the restrictions of GEDCOM, because that’s the way we can communicate with the sites, including My Heritage. I have my tree there, and on Ancestry, Geneanet, etc.
And when I look at my tree, many names that were registered before the French introduced the civil registry have the patronymic part in the surname. And in our case, most times, it does not have the inflexion that I know from Scandinavian countries, including Iceland, and Russia.
When surnames become habits, which happened much earlier in cities, and in noble families, I move the patronymic part to the given name, because that works best for grouping, even though I know that they’re not real given names, and not middle names either. I know what the middle names in your example mean, and I know that they’re not real middle names.
I have a real middle name, which is Frank. And it looks a bit patronymic, because my father’s given name is Franciscus, meaning Francis. It was registered as a middle name however, and my father has 4 of those. And his call name is Frans, which doesn’t fit well in Gramps either.
I’m fully aware of the problem, and I compromise, because we have nothing better than GEDCOM 5.5.1. The problem was solved in GedcomX, but nobody uses that.