What happens if I forgot to get my TM30 stamped within 24 hours of arriving back in Thailand?

The poster forgot to get their TM30 stamped within the 24-hour requirement but later learned from responses that immigration in Chiang Mai is more lenient. They were able to get the stamp without issue despite being late. It appears that the strict 24-hour rule applies primarily to the original notification of address, and the timeframe for stamping after returning may be less stringent, especially if immigration offices are closed on weekends. Other commenters shared similar experiences of not being fined when late.