We're looking to replace our old, cracked V&B Omnia Classic toilets with https://www.villeroy-boch.co.uk/bw/m/O.novo-Washdown-WC,-rimless--5660R0.html . The measurements of the important bits line up. Our old ones are not rimless, but these are. On the product page, it mentions:
DirectFlush. Sanitary porcelain. Also available in CeramicPlus. not suitable for installation with flush valves.
Does anybody know what "not suitable for installation with flush valves" means?
For what it's worth, our flush consists of: