@Vin ********
I have applied for an OA Visa in 2017, 2022 and 2024. In 2017 health insuarnce was not required. For 22 and 24 the LA Consulate required health insurance documents that proved the policy was valid and was in efffect as part of the applciation on Evisa. The Evsia also required flight reservation fo Thailand. This was the Los Angeles Thai Consulate so if you do not appy with them then your applicatiion experience could be different.