I suspect that, if a comprehensive search was made of old photos, a number of royal ladies will be seen to be wearing stars pinned through their sashes or in areas where there is a denser fabric (such as a belt/waist area etc).
I know that Queens Alexandra and Mary of the UK wore a lot of dresses made of lace and other delicate fabrics. I have read that both had their bodices reinforced with buckram to enable them to wear heavy brooches etc. Perhaps that is so as, unless undergarments provided a base, I do not understand how the Cullinan diamond brooches and other substantial pieces could be worn without causing a significant pull on the material of their dresses. Similarly for the Dutch royal ladies and others of that era wearing their very substantial brooches/stomachers.
I suspect that reinforcement of dresses is no longer done on a routine basis by most of the younger royal ladies.
On the other hand, I think that, because of the type of fabric of her dress (lace), her jewels and where they were positioned Queen Maxima may have had special reinforcement to the dress she wore for her husband's Inauguration.
I think we may have to rethink what we have supposed are "the rules" about where some decorations should be worn.