Using external (windows(), x11(), etc) graphics devices in Shiny

I'm developing a Shiny project for visualizing data and find it convenient to use an external graphics device (windows()/x11()) sometimes so I can control size and aspect ratio of a plot. This seems to work find except that the usual 'right-click on the plot' gives me a popup with no visible text, even though the functions appear to work (I right click and see what happens). My questions are a) is this a good idea? and b) how can I restore the text in the popup menu?

Is your app expected to be deployed on a server? because on a headless server, you would not have windows()/x11()

No, it's just for the use of my team on individual computers.

I've just discovered by chance that if I use windows() to open a plot window from the RStudio console and create a plot, the right-click popup menu has no text, the same as from within Shiny. However, if I close the Shiny project and do the same, the menu text is normal, even if I load the Shiny library (library(shiny)). I'm never sure if odd behavior is a bug or my own lack of experience, but this seems odd.