My experience with Quarto has been quite positive. You can treat it as if it were RMarkdown but allowing for Julia or Python or R code execution. To me the fact that the Julia and Python code execution is carried out through Jupyter is incidental in that I regard the .qmd file as the source, not the .ipynb file. If you want to use .ipynb for interactive execution that can be done using quarto convert as you indicate but I prefer to edit the .qmd not the .ipynb because of the problems with out-of-order execution, etc. in Jupyter. Also, to date it doesn’t seem that the YAML markup, and code-chunk options or cross-referencing/bibliography facilities in Quarto show up natively in Jupyter.
I tend to use quarto preview, quarto render and quarto publish much more than I use quarto convert explicitly (it is implicit in all the other commands I mentioned). Much as I love Pluto notebooks, I would go with Quarto for course materials for the cross-references, bibliography, equation markup and figure/table styling.