(They sell a silly, overpriced case).
Fireboard gizmo took less than a minute to configure via BT, which detected the device from the app instantly.
Fireboard takes 100K thermistors and ships with three of them (1 ambient and 2 product probes).
So, until I find a better gizmo or this one blows up and I eat my words: this is the gizmo I currently recommend.