Ahh, @PatoPato, I feel you!
Thanks for the encouragement on earlier re Hampton. It's very much down to interviewers at this age (and, based on my own experience, for a considerable length of time thereafter), and you just can't control it.
The "big sighing noises" made me laugh. My DS does exactly that when he is stressed through a challenging problem, but, luckily, all've been spared of this, as none of ours were via Zoom.
Mettle was ok, but personally felt a bit re-purposed and unpolished. Also, faffing around with the QR-codes, when it turned out that I could just use the existing scanner, was unncessary.
Anyway, nearly done now, and we'll be able to laugh about it eventually, I am sure!