Just thought I'd share this with the group. Have seen some confusion about whether or not the drive-up window for 90-day reporting is still open at Chiang Mai Immigration near the airport. Simple answer: Yes, and they do walk-ups as well, but closed noon-1pm for lunch break. Super fast and courteous service. =)
TLDR : Answer Summary
The drive-up window for 90-day reporting at Chiang Mai Immigration is currently open. Walk-up services are also available, but the window is closed for lunch from noon to 1 PM. The service is reported to be fast and courteous.