But what I'm really looking forward to (not) after 2019 is shuffling along in the 'NON-EU' queue at immigration/passport control whenever we enter an EU country, while he and DS sail through ahead of me in the EU-only line
Don't worry the rules have already changed because of the UK (and Ireland) not being in the Schengen area. I was in a 25 minute queue at Zuerich airport last week - and that was short compared to some of the poor holidaymakers going to Spain etc having 4 hour waits.
What you really want isn't an Irish passport but a Schengen area one.
Mind you, having holidayed in Germany very close to the Swiss border I am now really wondering what the whole Irish border hoo-hah is about. Germany is in the EU, Switzerland is not. Both are in the Schengen area but I don't think Switzerland is in the customs union.
If you are walking around the town (Constance) you can simply walk around. No border controls at all. There is a boat that goes along the Rhine calling at Swiss and German towns on each side of the river. No border controls. They say you have to have a passport but there were no checks and I think you are technically supposed to carry one anyway in Germany.
There did seem to be a proper border stop on the motorway with a short queue.
But it seems to me that it is entirely possible to have a sensible border arrangement with a non-EU state and the EU should just let the Irish and UK governments continue with the Common Travel area. I simply can't see where the issue is, especially given the history.
Mind you, the best solution of all would be to stay in the EU and move on from all this nonsense.