(NCS 3.1.0, mfw 2.0.2, nRF9151-DK)

Build:

west build -b nrf9151dk/nrf9151/ns -p -- -DSNIPPET="nrf91-modem-trace-uart"

(Please note: in general, the snippet must be applied to the app only,
which requires to use -D<dir>_SNIPPET="nrf91-modem-trace-uart".
Here McuBoot is not used ... so it works without.)

Using the Cellular Monitor App the shows on my machine, "it works".

prebuild image:

nrf9151dk-ncs3.1.0.hex

apply with:

nrfjprog --program nrf9151dk-ncs3.1.0.hex --sectorerase --verify -r

