I just did it on a 17 sidewinder like 2 weeks ago. used the TKI kit and it wasnt bad at all. had to buy the long chain case obviously but did a belt drive as well. and yes i know i lost my reverse and i hope i dont regret it lol.I haven't tried it, but you may be able to do a drop/roll by using King Cat or 2018 and up Sidewinder MTX chain case. Probably would be easiest to find someone that is parting out a King Cat/2018 Sidewinder though.
Also there was a thread in the proclimb section (2 stroke) where they were using the newer D/R chain case parts. I believe someone had posted instructions for modifying the mounting location on the clutch side as well.
Told on Facebook viper forum it couldnt be done. My 15 Mpi viper had 7 tooth with a 2.6. Just put in 8 tooth with the 3" and because of tunnel cut for header it went in easier than when I put in a 2.8 Camso on my 2013 M8 with 8 tooth. Lots of clearance to header and approach angle better. Track rolls easier too. Trying it this weekend. 3hr swap including pressing drivers.