I am quite certain they do not oppose laws against making false statements to investigators, lying about income/losses on tax returns or shareholder reports, making violent threats, and etc.
Those things are unlawful because of the effect they directly cause to the real world.
Speech, in general, is just sharing information - it does not cause any direct effect on the real world (actions of other people with whom we have shared the information do not count as direct effects, or otherwise the legal system would get really messy).
Every action has effects on the world. If we go down that path we might as well ban thoughtcrime, because criminal thoughts have effects on your mind, making you more probable to actually commit a crime.
Note the word "direct" in the sentence you have qouted.
As you say, there are no free speech absolutists.