won't heat kill the codeine?
Apap solubility is about 14 mg/mL of room temp water, so you could have more than 10g of apap in your extraction. The most you can safely consume over the course of a day is 4g, and that number can be less if you drink alcohol or have pre-existing liver problems.
In the future, you can probably use less water
does this mean that if you only used 100ml of water in your CWE, the most APAP you would be consuming is 1400mg, which is well within the safe dose?
Yes, but only if your filter catches 100% of the insoluble apap. Generally, you should assume that your filter isn't perfect, because it probably isn't.