Hi Ronnie, the rules around project templates/box is now that they also have to have the project as the profile manager or one of the profile managers and that is usually reserved for profiles that are "highly controversial profiles of historically-significant people and widely-shared ancestors". Project protection is different again.
If you just want to indicate that a profile fits within a project, for instance you want to indicate that Georg von Glasenapp is an European aristocrat than you can add a sticker instead of a template.
The sticker for European Aristocrats is
{{EuroAristo Sticker|place=Castilla}} where you replace Castilla with whatever country is appropriate.