Are the Spanish royals the only ones who side with Prince Pedro, as head of the royal house of Bourbon-Two Sicilies? Do all the others
(in particular, the heads of the other houses) support Prince Carlo, the Duke of Castro? What do they think of him naming his elder daughter, Princess Maria Carolina, as heir?

What about the other divided houses? Is the claim of the Grand Duchess Maria Vladimirovna of Russia, as head of the Romanov imperial house, largely supported by others?

Or the Brazilian dispute? I know that there are quite a few contested claims in these non-reigning houses. It's understandable, since a dynasty cannot easily clarify the succession or change rules, after getting deposed. That's why once sees qualifiers and disclaimers such as "Archduke George of Austria is the only one of his parents' seven children to have married in accordance with existing Habsburg house laws ... he and his son would eventually succeed to headship, under the said laws ..."

What side do others take on the Austrian dispute, for that matter?