As well as a summary of the situation (both in the ATmosphere and the Fediverse) and links to a bunch of interesting discussions, there's also a discussion of just why age verification laws are so bad.
For resources and opinion on Online Safety Act I would also mention Neil Brown, English internet, telecoms, and tech lawyer at decoded.legal, who wrote several articles on the topic, and maintains a dedicated website:
Tthe Mississippi law is very different from the Online Safety Act. For one thing the Mississippi law applies to all social networks, as opposed to the OSA where there’s a lengthy process to go through to see whether it applies. Also, OSA regulators have said that geoblocking the UK exempts you; we have no idea if that’s the case in Mississippi.
Neil’s pages are great, but I haven’t seen any guidance yet on compliance with the MIssissippi law.