Extension using dynamic menus has no scrolling when it grows larger than screen

Short version: Could Jupyter Notebook do something sensible to handle menu entries that are larger than the visible screen? The current setup is such that it is not possible to scroll down the page in the browser to see "further down" for menu entries that are "below the fold" -- attempts to do so result in the menu in question disappearing.

Details:

Pulled over from `nb_conda_kernels` repo issue: https://github.com/Anaconda-Platform/nb_conda_kernels/issues/121 where the extension maintainers said they couldn't really do anything about this -- it has to do with the way Jupyter Notebooks handles nested menus.

Extension generates a list that goes off screen, no way to scroll down


these go below the fold on my screen and I have no way of selecting the ones I cannot see. The only (unsatisfactory) option is to dramatically reduce the font size until they all show up. Is there some way this could be fixed?

Reproduce the issue with the dynamic nested menus from nb_conda_kernels issue 121 and inspect Jupyter Notebook's menu handling. Done means menu entries extending below the visible screen can be reached and selected without the menu disappearing.

Written by the indexing model from the issue text.