Maybe Francis an his minions are guilty of the sin of heresy, maybe they are not (God knows), but what is certain is that they are not notorious heretics (public heretics) since they never explicitly and directly deny any dogmas.
One can be a heretic without explicitly or directly denying dogma. In fact, to subvert dogma by implicit and subtle means is a greater sin because it shows a predetermined agenda and planning.
Just like premeditated murder is much, much harder to prove than a sudden-bar-fight-turned deadly, the former crime is much much worse than the latter, which is a case of situational aggression gone awry. Often people can get away with premeditated murder because they can hide the evidence while a bar fight usually has many witnesses. Both both cases result in murder and death.
The point being, the legal system (either secular or ecclesiastical) is limited as it is a fallible institution. We can’t look to canon law as the sole judgement of heresy because there is also doctrine involved.
Canon Law may be insufficient to judge (on earth) such horrid, satanic heretics as Francis, but many saints, like St Paul, fill in the gaps by telling us to declare such “anathema”.
Catholic common sense is able to reject these people even if the (fallible, limited) canon law must wait for (human) justice. “The wheels of justice turn slowly” is a truism; this does not mean that such heretics cannot be “judged” in the public realm of catholic ideals. In fact, they should be judged, avoided and repudiated as St Paul and St Bellarmine (and many others) tell us.