I could just remove that specific [+special:strings] but it's there for a reason, and it's to make source text more "stable", so that translations need less updates.
I should use it even more, actually.
But that problem is compromising the very sense of that feature, impeding people to make translations
One possible solution is to have an alternative to the + operator to prepend instead of to append. As symbol I would use ^ .
Prepending would give priority to the customization.
This should be quick and easy to make for me, and technically good.