When using the single stage build w/ finalization method, is it beneficial or required to run the warm up process in the build as well?

Single-Stage With Script Finalization
You may also create this finalized startup script in a single-stage build:

FROM ortussolutions/commandbox:lucee5

# Generate the finalized startup script and exit
RUN export FINALIZE_STARTUP=true;$BUILD_DIR/run.sh;unset FINALIZE_STARTUP

It's required. Finalization actually removes CommandBox, so if you've never started the server, there won't be an engine there at all, lol