DTV is technically not a long term resident visa, but a tourist visa with a stay of 180 days, but 180 days might be enough for Chinese embassy in Bangkok.
The graceperiod does not prevent the need to do second report in case your first was before day 90. It only gives you the possibility to report sooner or later, but you have to report.
ThoughtfulLychee5096 You always have to pay tax somewhere. Not paying tax somewhere is not a gray area, but black, and very unfair to let others pay for you.
Keep in mind that reporting in the 2 weeks before 90 days is reached means the next reporting day will be before day 180 of your DTV stamp, which means you need to do a second reporting if you want to stay the full 180 days.
As I said before, but you have missed that obviously, "you NORMALLY", so some countries might have other procedures for this.
When you say flatly false, maybe you should give an example of a country that has a different procedure, and describe that procedure.
Maybe when I show the official text from your home country about this:
Report your Visa Lost/Stolen to the U.S. Embassy or Consulate Abroad
To report your visa lost or stolen, email the Consular Section at the U.S. Embassy or Consulate outside the United States which issued your visa. Go to the U.S. Embassy or Consulate website to locate the email address and contact information. Be sure to include your full name, date of birth, place of birth, address in the United States, and an e-mail address (if available). Specifically state whether the visa was lost or stolen. If you have a copy of the passport or visa, scan and email this to the embassy or consulate. Otherwise, if known, report the category of visa, and the passport number from the lost/stolen visa.
If you have already reported your visa lost/stolen to the U.S. Embassy or Consulate, and then you later find your misplaced visa, then your visa will be invalid for future travel to the United States. Therefore, in that situation you must apply for a new visa at the U.S. Embassy or Consulate.