why wouldnt you? that dual mass is just a blown tranny waiting to happen... many people have had tranny's shot due to it coming apart... mine was almost seperated when I got my clutch and fly done... you could literally take both parts and move them around like they were nothing... the mechanic said he's surprised it didnt come apart already...
my only thought is, imagine driveing your freshly boosed svt pulling out onto a highway and for the fun of it seeing what you car can do, accel to 7000k rpm and BOOOOM, you have a hole in your tranny case!
I dont know, just think about it... you'll have it down anyway for the clutch