^I had the same problem as you when I first looked around Dunhua. I couldn't find CLS or Trinity either (maybe they changed locations?). Anyway, you should check out UnderxPeace (don't confuse it with Undercover). Dont know what brands you are looking for but when I was there a couple of weeks ago they had some BAPE, BBC, Vis, NHBD and a grip of other things. It should be located in the same area as Co-Oper and is right next to a store called Axis.
Another store that I found in Dunhua that's located in an area off the map that was posted here is JP Show. Quick run down of brands they carry were Wtaps, BAPE, Supreme, NHBD, Bounty Hunter, Original Fake, Fenom, and I saw a couple of Vis shoes too. It's located right across from this bomb ass restaurant called Yumas (one of the few places that sell Mexican-ish food in Taiwan lol). To get to the area you have to take Exit 3 from the MRT station, I think? All I know is that it's the exit across the street from where you usually pop up w/ California Fitness on top. To make things easier here is the address for Yuma's: Alley 11, Lane 216, ZhongXiao E Rd, Section 4.
Lastly, you should check out the stores in Ximen namely XSPC (sells Supreme, CLOT, Original Fake, BAPE, and Vis) and Tokyo (sells almost the same thing as XSPC) found in Shinjuku plaza. There's also a place in there that sells Comme De Garcons but I don't know what it's called. Oh and good luck finding Support somewhere in Ximen while you're there too lol.