@David ***
By law it's required, but it'll never be picked up. Pre-covid I lived for nine years in Thailand on OA visa, using the border bounce to get the free year, and returning to my home country for a visit every two years, picking up a new OA in the process. In those nine years I never had to transfer money into a Thai bank account and never went to an immigration office. Covid killed that but now it looks like it's back on track! I was never once queried about 90-day report, and if absolute worse comes to worse it's a 2000 baht fine. Some people pay more than that to agents to do it for them!