AS IT IS and AS IS (AS as a conjunction and a pronoun)

Looking at the idiom "as is", I see that it's used for damaged goods on sale, but Collin's examples are not used in this manner.

• It's a way of shaping the new year according to our will, as is the practice of making predictions. Wired (2004)


• Detectives are investigating the man's death, as is standard. Seattle Times (2004)


• The researchers gave baboons and monkeys the same amount of the drug as is often taken at all-night rave parties. Chicago Sun-Times (2002)

So.. when it's 'as it is' (OK. It was my bad assumption.) you omit the 'it'? For example,

We were hoping to finish it by next week—as it is, it may be the week after. (Oxford Learner's Dictionary)

Can I omit the 'it' and say "…as is, it may be the week after"?

As suggested:

Collin's definition for 'as is': (US)(informal) just as it is; without any changes (said of damaged goods being sold) [the source]

But Wikipedia says it's a legal term. [the source]

Oxford Learner's Dictionary talks about 'as it is': "considering the present situation; as things are". [the source]

Answer

The answer to your last question is no, you can't. On the other hand, you could add an it into the phrase sold as is and convey the same meaning. As it is has the meaning of "in the present state". If you find the words as is with this meaning (and I can't think of any usage of the phrase that does so other than the "damaged goods for sale" one that you have brought up), you can add the "it" into it. However, you can't take it out and keep the meaning.

Now, the other examples of as is that you have either mean which is or that is; your examples where as is preceded by a comma can substitute which, and the other can substitute that, without substantially changing the meaning.