A planning forum held in May 2020 voted 87% in favour of Remit 5, that is to allow the use of Hoof Boots in Dressage competition. See minutes.
There are some stipulations as to colour (black or brown only), the boots to be lower than the coronet, and not to cover the heel, as well as to be easily removable by veterinarians.
It was decided to form a sub-committee to further clarify what that means and what type of boots are going to be allowed under those rules.
It appears the boots below are acceptable for dressage competitions: