Source Control / Roon extensions

I am working on a modification of the roon-meridian-extension for controlling my T&A DAC8 via RS232. Volume and Mute is working, Source not yet stable. here my questions:

How the final UI for source control should work? Changing the source via drop down menu in the roon settings/extensions or is it a button somewhere else, for example in the volume control area of the main roon window? (I don’t have any of the devices for the existing extensions on hand to check, how the result should look like…)

I am a bit confused about function of the different variables & definitions in the code around the “Source” function:

  • displaysource // Where is it displayed ? why display source and set source?
  • setsource // changed by the dropdown menu
  • convenience_switch // Where is that switch ?

any help is appreciated,