Private VIs in subpanel breaks PPL

[Basjong53]

I have a program with a plugin structure. Each plugin has its own front panel and can be called from a dropdown menu that is dynamically populated based on the available plugins in the form of a PPL.

I have a problem with one of my plugins. The plugin itself has a subpanel which loads one of 2 different VIs. The logic and the panel to be displayed is wrapped in a class like this: (SpecPanel and DiodePanel are children of LumPanel)

The panels are started like this:

I made the panel VIs private since only the class should be able to access it. But when I do this, the VIs disappear from the PPL and the main plugin loads broken:

When I make the panels public, the plugin works fine, so I'm leaving them public for now. But what would be the best practice going forward?

[Yamaeda]

Set them Protected or as Friends.