The simplest way I solve this with my SD cards and SubWayUSB with a multi card reader is to create a new Mountlist in Storage;DOSdrivers/ called SDC (Short for SD Card)...
Then in Trident on the masstorage page click on the LUN Settings Tab and change DOSName to SDC
Now when you insert different SD cards instead of UMSD.1: etc.. coming up you'll get SDC: and the name of the card for example "My Pictures" or the usual pre allocated name/number, for example "1764_0891" if you haven't renamed the card...
Much better than having UMSD.0: etc... popping up all the time...
The same would apply to your CF cards just create a mountlist called CFC for example...
