I made these yesterday. I had 500 grams of lamb instead of the 300 grams as per recipe. I had to turbo a few times extra to combine it all, but this would have been because of the extra quantity.
I cooked them in my new Rank Arena airfryer which I bought this week (I already have a Tefal Actifry, so I'd not bought myself a Phillips airfryer - but the RA was only $90 from Deals Direct and seemed to have good reviews, so I thought why not!). It seems quite good, I've used it a bit the last couple of days.
The meatballs were lovely and I'd definitely make again.