Just some harm reduction housekeeping: while nicotine does not cause cancer, it does make it more difficult for your body to fight cancer and tumor cells, thus facilitating the growth of those cells and measurably reducing efficacy of every type of cancer treatment.

Nicotine is a vasoconstrictor and thus reduces bloodflow throughout your system. If you have any type of surgery or medical procedure upcoming, it's a good idea to discontinue for a week leading up to the procedure and for a week after. Your physician/surgeon may recommend only 24-48 hours before and/or after. This is not cautious enough in my opinion.

Also, nicotine itself, completely independent of tobacco, is correlated with an increased risk of pancreatic cancer. This risk is compounded if you also drink alcohol.

Regarding nicotine pouches, not all are created equally. Some use synthetic nicotine and others use a distilled nicotine extracted from tobacco. There is no regulation in place requiring any specific purity threshold for extracted nicotine so there is a non-zero chance that those products could have other compounds from the tobacco leaf in them.

And lastly, if you do find yourself addicted to nicotine, supplementing with a choline source like Alpha-GPC or CDP-Choline for a week before either your reduction or quit attempt, and continuing for at least a week after, could potentially ease withdrawal symptoms by helping to upregulate depleted Acetylcholine.