Forget towel radiators and fit a conventional radiator with a couple of heavy duty rails above it.
In our main bathroom I used, Rothley Endurance <span class=”mark6p9w8afag” data-markjs=”true” data-ogac=”” data-ogab=”” data-ogsc=”” data-ogsb=””>Stainless</span> Steel Hanging Rail End Brackets 25mm, spaced them off the wall with some CLS battens painted to match the walls. fitted 2x 1200mm rails, there’s enough space to hand 4 full size bath sheets, the towels are bone dry within hours and they are heavy duty enough the kids haven’t been able to pull them off the walls.