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"?
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]