I have written Julia scripts and accessed different Julia libraries without issue in Jupyter. I have not noticed any limitations on its use or any performance degradation. I imagine some aspects of Julia that are very screen dependent (such as using the Julia webstack to build a website) may be hampered by conflicting uses of the same concept.
I have repeatedly seen updates being run when I am attempting to run a Julia script, as shown in the following screenshot. I am not sure why they decided to always update the underlying tool rather than use what is in play and have the user specify whether to update libraries:
I have also noticed that once a Julia Notebook is opened, even though I have closed the page, it will still display Running on the home page. I don't recall seeing this behavior with the other script languages that are available...