Been in and out about 5 times now on my DTV and never had a significant problem. I always make sure to dress decently and greet the IO politely. The first time I went through with my DTV there was some confusion because the IO had never processed one before, but only took a few minutes to sort out with her supervisor's help.
Best to just stay away for at least six months - that was the warning I got from the Thai Embassy in Singapore when applying for back to back TR visas after getting warned by an IO for entering too many without one. Got past all that eventually by getting a DTV.
You can try entering via land from Malaysia - supposedly they are more lenient and it’s a lot cheaper to leave if they refuse you entry. I wouldn’t risk it personally.
Seun Handyman you need to have a current TM.30 to do your 90 day report, yes. If you haven’t left the country you can still use the TM.30 you did when you (re)entered Thailand.
So my gf went down to do her visa extension after paying the landlord to update her TM.30 the night before. Apparently it takes a day or two to process because when she went to immigration they said her TM.30 wasn’t valid and tried to fine her 3000 baht. She ended up doing a border run to restart the clock instead.
Moral of the story is don’t put it off to the last minute like we did. Be aware that immigration has to process and formally accept the TM.30 report online before it’s “official”.