Is Mbed compiling locally possible?

Yes, it’s possible.
Use their manual to install the mbed-cli
Then set:
mbed config -G
Use for example in linux: mbed config -G GCC_ARM_PATH “/usr/bin”
-G flag makes settings global
Use that command to:
GCC_ARM_PATH
TOOLCHAIN GCC_ARM
TARGET NRF52_DK
In the end check with
mbed config -L
Clone repos with
mbed clone < address >
Compile with
mbed compile
If there is an error with the libs and you get prompted to use “mbed deploy” and it does not work, try to delete all folders which have a *.lib with the same name. Then run “mbed deploy”.