I ordered from OSHPARK and to the UK they're just as slow as the Chinese suppliers that give you 10 boards for the same price, so I probably won't use them again.

The module was so tricky to solder compared to the ESP8266 ESP-12F. The castellated pads are too small to do individually with an iron. I managed to lift the bottom most pin on the left (luckily NC) trying this.

In the end I fluxed and tinned all the pads using the drag method, then fluxed the bottom of the module, aligned it and applied light pressure on top with my tweezers, then directed hot air at the pads and the solder melted and the module sunk into place. Probably not the best way to do it, i think it really needs to be reflowed but I might try the 'blob and suck' method I've seen used on QFN chips on the next one.