The trip taken to the Northern Ireland border by David Davis, Greg Clark and Karen Bradley yielded one unambiguous result, according to one of those there.
The Brexit secretary, the business secretary and the Northern Ireland secretary were told in no uncertain terms by representatives of all faiths, all communities and all parties - including the grassroots DUP, if not its leadership - that they don't want any discernible changes in the way goods and people flow across that border.
Unsurprisingly, the locals adore living in peace. And they don't want anything that brings a risk of a resumption of gangsterism or terrorism.
Such at least was the read-out I was given.
Which might be obvious to you. But it has political significance.
Because it means that these senior ministers are with the PM in her argument contra Jacob Rees-Mogg and the European Research Group of backbench MPs, whom she sees as under-estimating the risks of a return to instability and even violence in Northern Ireland from the imposition of even the lightest of border checks.
Now to be clear, it does not mean that "Max Fac" - or a tech solution to the question of how to sustain frictionless trade with the EU, in Northern Ireland or Dover - has been proved useless by these three members of Theresa May's Brexit war cabinet, dubbed "SN", who were charged by her with kicking Max Fac's tires.
I would still expect the Cabinet ultimately to opt for Max Fac over May's preferred option - called the New Customs Partnership, which would see the UK three-quarters in the Customs Union - as at least part of a plan to maximise trade with the EU.
But the customs argument is - in truth - a bit of a sideshow.
The big unresolved question is how far and how long the UK would continue to adopt EU standards for goods, foods and services.
And what the ministerial troika's mission to the Irish border probably proves is that there will have to be close alignment between the UK and EU on rules and standards relating to foods and goods, under the hated sway of the European Court of Justice, for months and even years.
Because, for the EU, border checks are more about verifying product and food safety than tariffs (which is especially true if the UK agrees a free trade deal with the EU - though stuff from the rest of the world destined for the EU but passing through the UK would still have to be monitored, for tariffs and standards).
This sort of alignment, which quacks like backdoor membership of the Single Market, would be necessary to make Max Fac work in the long term.
It would also need to underpin the prime minister's new offer to the EU of an all-else-fails backstop proposal to keep the Northern Ireland border open - which she's desperate to see accepted by the EU at next month's summit, so that substantive talks can at last start on the UK's future relationship with the EU.
None of which is especially cockle-warming to the more ardent Brexiters like Gove, Johnson, David and Rees-Mogg.
Which begs the question whether they ever wake in the middle of the night wondering what the point of leaving the EU might be, in the absence of an abrupt or hard rupture from the EU, since so much of the government's negotiating and planning effort for Brexit is directed towards creating a legal and technological structure of baffling and byzantine complexity, whose whole aim is to sustain as far as possible the commercial benefits of EU membership.
It is almost as though the prime minister's heart isn't really in Brexit. But that can't be so, can it?