"No cell block output is ever truncated. Accidentally printing an entire 100,000+ row table to a Jupyter Notebook is a mistake you only make once." Hah, sadly this is not the case for me.
Jupyter now has output rate limitations (I pushed for them to add them), though I think they may be off by default. I also implemented something better (I think), which is an output buffer, for CoCalc's version of collaborative Jupyter notebooks. Instead of rate limiting, CoCalc saves only the last part of the output, discarding earlier output, and provides a link to get it.