I would be grateful for some advice. Should I line the bathroom wall top to bottom with Marmox boards and install the bath against it and then tile, like in attached photo? Or is it better to fit the Marmox board over the lip of the bath? A tiler told me that doing the latter will create a better seal. Would you agree? If so, I should I cut the Marmox board at bath hight and slide in the bath a few millimetres and seal the 1-2mm gap. What would you advise?