S6/S7/RS7 exhaust on an S8?

I have found a good deal on an aftermarket exhaust for an S6/S7 locally. I think I can make it fit my D4 S8 with one small change. Has anyone done this or know of it being done?

I could be wrong but it is my contention that the exhausts are dimensionally the same with the exception of the length, the S8 being a bit longer. Apr even sells an extender for their DPs for the S8 https://store.ngpracing.com/apr-s8-d...r-fit-kit.html . I think that the distance between the mufflers, pipes, etc. are the same between the two and that any difference in width in the cars is accommodated by a rear bumper cover that has exhaust exits closer to the sides of the car. It seems that a single aftermarket DP fits all three models except for the length. Furthermore, for packaging and manufacturing, it seems unlikely that Audi would make 4 different muffler cases, differently bent pipes, etc for very small dimensional differences in the cars and all the different tooling to go along with it. I know they have different part numbers but I think that may have to do with baffling, etc.

Does anyone have any thoughts on this?