I think it is because if the tap handle doesn’t overhang the sink then wet hands drip water over the bench behind the sink. I have an undermount sink with same issue due to required setback from sink and we are learning to shake hands before turning off tap. Pro for wall mount no gunk around base of tap Negative according to my husband who refused to have wall mounted is the tap connections are in wall so if you get any leaks it’s hard to fix. But this goes same for shower I guess. We did have a faulty basin tap that leaked inside the handle area and down into cabinet so had to get replaced so I didn’t-push for wall mounted again.

Have seen many vanities butted up against walls on all 3 sides and 2 sides as well as the usual wall below a mirror. No idea of operation of drawer/etc. until one was seen in the flesh. Depends on hinges, etc., what its being installed near, etc. Basin top taps are probably easiest to install. They also generally use a stop cock to turn water on or off (for maintenance & the like) underneath the vanity with the basin top taps. More aesthetics than anything else really.

Does anyone have any experience of a wall mounted cupboard, that the ironing board folds down? I have found a Robin Hood version, available from Bunnings, but am keen to see any to compare. Thank you in advance for any replies

I agree with me me, attach the stop to the door. Place it exactly where you need on the door. Close to the hinge would work. We have an external door, which we wanted to stop from hitting the rendered external brick frame. We put the stop on the bottom of the door. Works perfectly.