If you're doing a hard Brexit with essentially zero chance of a free trade deal being worked out in 2 years (which you need goodwill for) then you kind of
have to do this. You can't leave without anything to fall back on, whether the EU likes it or not.
Even more significant is that any free trade deal is likely not bilateral, instead it would have to be ratified by all member states (apparently), we know this since the EU essentially changed the rules to that at the end of the CETA negotiations with Canada.
Assuming the court doesn't give veto powers to Ireland/Scotland/Wales, it's a guarantee that we'll see another vote for Scottish independence, no?
The polls show that Brexit barely moved the dial. One act of economic self-harm should not undue over 300 years of effective union for even more self-harm.
As for veto powers, that seems unlikely. England has 84 percent of the population, so it would be politically untenable for regions with 3-8 percent of the population to be able to veto legislation. Far better if nothing comes up that's as divisive as Brexit ever again, and Labour gets its act together (by dumping you-know-who).