With the case off you can get a little more range, but yes, it's not huge.
There's a little surface mount resistor next to the IR LED, and you could try shorting that out to increase the transmit power - for small bursts of IR it wouldn't cause a big problem and would increase the range.
You could also just attach a normal 5mm IR LED from a remote control, which would help a lot - and you'd then just have to use the IR code from here with it: http://www.espruino.com/Pico+Infrared
As @MattC says, for max power you'd need to rig up something with a transistor (which may be slightly harder because of the way Espruino normally does IR, using one pin for the oscillator and one for signal). However using a 5mm IR LED on the Pico you get pretty good range - I don't think Puck.js should be much worse.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
With the case off you can get a little more range, but yes, it's not huge.
There's a little surface mount resistor next to the IR LED, and you could try shorting that out to increase the transmit power - for small bursts of IR it wouldn't cause a big problem and would increase the range.
You could also just attach a normal 5mm IR LED from a remote control, which would help a lot - and you'd then just have to use the IR code from here with it: http://www.espruino.com/Pico+Infrared
As @MattC says, for max power you'd need to rig up something with a transistor (which may be slightly harder because of the way Espruino normally does IR, using one pin for the oscillator and one for signal). However using a 5mm IR LED on the Pico you get pretty good range - I don't think Puck.js should be much worse.