My experience staying on OA-visa in Surat Thani area. I'm living now since 6 month on an OA visa in Thailand. This is a short info about Surat Thani immigrations. ( Not Koh Samui! ) After my landlord applied for TM30 online reporting I'm using this account for TM30. ( How to do, search TVA there is a good explanation)
After 1st 90 day reporting in person to ST immigrations I'm now also able to use 90 day reporting online.
So it's a quite comfortable way to communicate with Surat Thani immigrations. ( Once again- Surat Thani Town immigrations)
Just to share my experience so far.