The earlier?? Juicebox units were notorious for over-hyping their current rating. My Juicebox Premium also lists 60a in big font yet has a 10 gauge J1772 cable(rated for 30a) as well as a 10 gauge 6' power cable(rated for 30a) terminating in a 14-50 plug(rated for 50a)
Of course with my Leaf it's fine as it maxes out at 27.5a but my Juicebox's digital display would let me set it to 60a
I know better than to set it higher than 30a but I'd guess that not everyone would, ahh the early days of EVs, kind of the wild west
To the OP, Juicebox has always made quality products, not always code Kosher but decently built. For $200 I'd rather have it than a cheap Chinese 16a portable unit. Unless it has WiFi to set charging current you'll have to take off the cover and adjust the trim pot with a small regular screwdriver.