My sincere apologies - I should have quoted the 1st November 2024
In reality, when I travelled from CNX to DMK on 14th November 2024, no such identification system was in operation - i.e. defunct!
Reference Google:
As of November 1, 2024, six airports—including Bangkok's Suvarnabhumi and Don Mueang, Chiang Mai, Mae Fah Luang/Chiang Rai, Phuket, and Hat Yai—now use automated biometric identification for domestic travelers.Nov 6, 2024