Update re TM30. I went to Chonburi immigration and they confirmed that if the residence address is the same as before, even when re-entering Thailand with a new TM6, there is no need to file a new TM30.
TLDR : Answer Summary
Recent updates from immigration authorities in Chonburi indicate that if a foreign resident re-enters Thailand and their residence address remains the same, there is no need to file a new TM30 form. This has been confirmed by multiple expats, although some variations exist at different immigration offices, such as in Jomtien and Chiang Mai, leading to some confusion. Expats are advised to verify the requirements with their specific immigration office.