They are a mix of people across the spectrum, there is no single position - there are stalinist nutcases like eddie dempsey and libertarian socialists and anarcho-syndicalists to straight up trad-unionists, to trots and republicans etc. I cannot see your reading as simply calling for a no-deal as correct. I can see that some my welcome it, some may not see it as the bogeyman and some opposed to that version of leaving the EU. I don't see why breaking with something cannot entail agreements as to how that break occurs where and when.
And if we don't leave we will be facing the same people in their liberal guise, with us defeated and weakened, beaten by a coalition of the left-capital with no path out of it for the forseeable, nothing opened up, in fact closed down. All opposition to the EU and its neoliberalism across europe crushed for the foreseeable future - a modern day massacre by the political descendants of MacMahon and the murderers of the communards. Whereas leaving (or just the threat of) has brought the delegitmation here of the status quo, of the political class, of the way things are run, the ongoing polarisation etc that all lead to potential crisis - and options. Recomposition that people on the far left have been calling for for so long.
So the same as them then? But they are trying to do it right now or at least proposing to start collective project to do just that. I think that you are losing sight of the fact that the EU is bad here and becoming bit too focused on the tories to the detriment of the wider picture. And make no mistake, the left party of capital is going to pay if they get this wrong. Which is what this is designed to highlight and then oppose.