As a Roblox developer, it is currently inconvenient that RobloxPluginGuiService does not show up in the Explorer under any circumstances.
Recently, BuiltInPlugins moved all of their PluginGuis to RobloxPluginGuiService. This was done for security purposes, and is understandable and to an extent convenient since it cleans up PluginGuiService. Unfortunately, RobloxPluginGuiService does not show up in the explorer though. Given that there is a setting explicitly designed to show all hidden objects and services in the explorer, it should show when that setting is set to true.
I personally used to look at built-in PluginGuis to determine how certain UI elements were sized or what texture they were using while designing UI that looked like Studio’s built in UI, and not being able to do that anymore will be inconvenient in the long run.
If Roblox were to change it so that RobloxPluginGuiService did show up in the Explorer when Show Hidden Objects in Explorer was set to true, it would make the setting more consistent and make it doable for me to look at how internal PluginGuis were set up.