Espruino Wifi with Adafruit Ultimate GPS - no data

The command cheat sheet has a comment about baud rate and update rate:

...it [the user] needs to see if the baud rate is enough or not.

I have no experience with the device you use, nor do I know if the baud rate of 9600 bps is fast enough to support update rate of 10 ups. I assume not, because the baud default baud rate was chosen to be able to transmit an update within maximal a second. (Updates have different lengths.)

You may need to start out with 9600 bps baud rate, set the GPBS's baud rate to 57600, then set your Espruino Board Serial's baud rate to 57600 as well (Serial1.setup(9600, {tx: B6, rx: B7});), and then set the GPS's update rate to 10.

Something else you can do in your parse: parse whether you get the expected acknowledge value.