For those guys looking to do 90-day reporting here at Chiang Mai immigration on 22 July, you MUST use the drive through. Yes, you can walk through it.
This is because those services are moving to the Promenada location. To my knowledge, the 90-day window at the main office by the airport will remain open for vehicles only after tomorrow.
Not sure if volunteers will be at the Promenada location or not.