merther, I like your location.
My copy of KOTOR2 has Securom 5 + Securom's famous emulation detection (none of their &*^(& business whether or not I'm emulating DVD drives!)
I think Frozen wants to be able to drop one DVD into the drive and be able to play the whole thing from disk without interruption. That ain't gonna happen, like you said, you'd have to keep changing out virtual images, and that ain't worth it.
Frozen, install the game to the hard drive, copy an image (SecuROM new 4.x/5.x with Alcohol 188.8.131.525), mount it on a virtual drive.
Then see Kill SecuROM Emulation Detection for how to get by the rest.
On second thought, if you're plumb out of hard drive space, it might be worth it. Just image all 4 discs (2, 3 and 4 have no protection) and use DeepBurner to burn all the resulting files to a DVD. Then you can go back and forth by changing the images back and forth in your emulator.