I no longer have a DSS monster to compare swingarms.
The bend around the swingarm will likely be a sticking point regardless of catless or not. Memory tells me there is no room for a pipe between the stock rearset and the swingarm on the Monster.
The multi exhaust does fit on the SSS monster if you cut that bend off... but I have raised the rear some, too.
Is the bend you are refering to after the 2 pipes merge & the cat attatches? If so that is a sign of good news. If it did work I was expecting to have to space the foot peg brackets out similar to when installing high mount exhaust, but that is also dependent on the pipe comming out in the correct possition. Did you post any pics of the install on the S2R? If so I will have to track that thread down & look. Thank you for the info.