Displaying the current tool number {after T0/T1/T2/...) on the screen would be helpful with MMU2 or other toolchanger.
The number can be displayed inside the nozzle picture.

After spending some time to debug it, I discovered that the project cannot be compiled on MacOS if -DCLANG_SUFFIX="-9" is passed. I have llvm@9 installed from brew and it gives the following error:

-- The C compiler identification is Clang 9.0.1
-- The CXX compiler identification is unknown
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Check for work

packBEAM should be also implemented in Erlang, so it can be integrated into existing Erlang and Elixir tooling in a easier way.