I've lived in Thailand for 16 years, have NEVER done a TM28 as Bangkok Immigration don't use them. The TM30 is actually a landlord or hotel requirement. The information goes into the immigration database, so there is absolutely no requirement to carry a copy in your passport. The only time I print a TM30 is the day before I attend immigration in case it hasn't shown up in their database. I do 90-day reports online - there is no requirement to show a TM30.
Ah ok. I won't allow anyone to staple things into my passport. That's how damage occurs. When I apply for extension I only print my TM30 the day before and present it with the rest of the documents
Why don't you just go to the search function at the top of the group page and type in ETA? This will bring up all 700+ posts on this subject. Or is that too difficult?