I have made one prototype of the TSensor board using the PCBA service from Macrofab. The prototype cost was about 120$, however the unit price for a small batch of 50 boards is about 40$. Prototype is fully functional and was tested with a Pmod TMP3 sensor and a Dragino LPS8 gateway.

The only problem with this prototype is the lack of user button as the BOOT0 pin can only be used to boot the Murata's module in "flash loader" mode.

Design files are available on this website (see "Files" section) under CC-BY-4.0 license. Feels free to use it and modify it for your own usage.