It seems that only markdown cells are included in llms-full.txt generated by sphinx-llm when including a jupyterlab notebook using nbsphinx. sphinx-llm uses sphinx-markdown-builder
The code cells and output are stripped from the generated markdown. Code cells should probably still be included, and ideally the output as well (if it's plain text, richer content like bokeh plots should probably not be included as there is no straightforward conversion to markdown).