This is a good module. Nice for HAM radio applications on 144 MHz.
Documentation is ok. A little more comprehensive documentation would be nice, maybe for the digital messaging in particular. What protocol, what modulation is used? FSK? How is data encoded?
There is an even smaller module available, SR_FRS_0W5, but for VHF you need to buy a larger number of modules. I would love to play with this as well. For applications that need some more transmitter power and it is not hard to add a PA module. For such applications, 0.5 watts output is more than enough.
There is a 2 watts version for UHF, but not for VHF?
If the module is put in deep sleep mode it seems to pull down the PTT input?