Insert button on Eucon devices should open the Audio Inserts Tab by default on an Instrument track, Not the MIDI Insert Tab.
I recently got an Avid artist mix but Instrument tracks in Cubase are super annoying. Whenever you hit or leave the inserts button lit up to mix the inserts on the selected channel, if you select an instrument channel in the arrangement window it will close the audio inserts tab on the screen and open the MIDI inserts tab. This makes it hard to mix in the arrangement window. If you hit flip chan and inserts it will let you edit the audio inserts but it still swaps the visuals on the screen to close the audio inserts tab and opens up the MIDI inserts tab instead. People are in almost all cases going to want to add and edit Audio plugins on an Instrument track when using Eucon control surfaces. They should default to control Audio Inserts on Instrument Tracks or at least give the user the option to make them default to control audio. I don’t see anyone buying a control surface to add an edit the very small amount of available stock MIDI plugins that come with Cubase. It’s much more likely they will be wanting to control 3rd party Audio Plugins.
This problem forces you to mix in the Mix window which is not ideal in many situations. The biggest issue is, just with them connected to Cubase, it forces Cubase to keep closing the audio inserts tab on Instrument tracks in the arrange windows and opening up midi inserts. So annoying. Often it makes more sense to mix and edit and the same time as well as being able to easily open up virtual instruments to turn off build in effects and reverb within the instruments themselves but you need to be on the arrange window for that.