Has the Descent Mk3 series fixed the usability problem in the Mk2 with useless gas switch prompts? On the Mk2 during a Multi-Gas dive activity when you ascend to a safe PO2 it will automatically prompt you to switch to deco gas. The problem is that the prompt completely blocks the entire display so you can't cross-check your depth against the deco stage MOD sticker! You have to cancel that prompt, execute the gas switch procedure, and then push more buttons on the computer to manually switch gasses.
The way it ought to work is the gas switch prompt should still display depth. Or you should be able to just disable that prompt entirely. (I submitted this to Garmin Ideas years ago, but they haven't fixed it yet.)