I haven't cold smoked in my UDS, but seems to me that you can use one of the intakes to get smoke in there, and there are many ways to generate that smoke. No need for drilling holes at all.
50" Klose BYC, 22.5 WSM, Backwoods Chubby, UDS, 26" & 22.5" Weber Kettles, Jumbo Joe, WGA, WSJ/MUDS, Jumbo Old Smokey, a piece of expanded metal I throw over the fire pit sometimes, Stealthy Black & Vol Orange
Displaced East Tennesseean
Proud recipient of a Tick
Former outlaw MOINK baller, now IMBAS Certified, but still lookin' over my shoulder.
"Relax, it's only BBQ.
" - Bigmista, 2013
Avatar by my son!