Upvote:1
As far as I'm aware, in all three countries, any registration paperwork is the host's responsibility, not the visitor's. So while you can always ask about registration if you want to, it's the host, not you, who could (theoretically) end up on hot water if they don't.
Note that in Thailand, long-term residents do have to register every 90 days or risk fines, but this doesn't apply to tourist visas. More detail on how the TM30 system works: https://www.thethailandlife.com/tm30-guide