Are all DLL files pre-loaded at game start up or loaded when needed?

Hello! I was wondering; Are all .dll files in the Managed folder loaded when the player boots up the game. Or do .dll files (plugins) load based on what is in the current scene.

For example; Say we have a plugin, which is not used in Scene 0, but it is used in Scene 1. Would the .dll be loaded anyway in Scene 0 or will it be loaded during runtime when you enter Scene 1?

I ask this because I am making an Android application that will have many plugins and I don't want to take up a lot of RAM space when certain plugins are not used until later on..

Thank you!