They look interesting, but the website doesn't give a lot of detail.
The concern with Disc brakes is always in regard to reversing.
In the UK trailers have to have auto reverse brakes, and if they don't that could invalidate your insurance following an assessor inspecting the trailer after an accident.
Edit, found a mention of auto reverse on page 26 of their catalogue which I found via the UK distributors website:
[I]"• problemlose Rückfahrautomatik
trouble-free reversing mechanism
Marche-arrière automatique irréprochable"
UK - https://www.marcar.co.uk/product_cat...s/light-axles/