As far as the physical address goes, I mailed my application packet to the DPS address that was on the envelope:
Regulatory Licensing Service, MSC 0245
Texas Department of Public Safety
P.O. Box 4087
Austin, TX 78773-0245
I sent it certified mail, return receipt......when I received the receipt, it was date stamped with the stamped street address:
Texas Dept of Public Safety
5805 N. Lamar 78752
I don't know if that's the central mail drop for ALLLLL of DPS or not. I'd suggest calling the CHL licensing unit, and getting the drop off address straight from the horses mouth to avoid any confusion or misinformation.