Hey Vinny,
I know you are a serious electric motorcycle enthusiast having an order in on a Zero back in early 2009 and since getting a 2014 SR and a year ago a 2016 SR. I have no doubt eventually Harlan at Hollywood Electrics will be able to have the parts to do both the things you mention. The front sprocket is different and stronger on the new belt system and so the motor shaft itself had to change. Someone is going to need to develop a sprocket with a keyway for the older bikes. But the reason it changed is because a single keyway is only so strong. If you upgrade the controller (not available yet to the public on sevcons website) this could be a issue. But perhaps not if you just want a stronger belt and don't upgrade the controller. Regardless it will probably be quite a while before Hollywood Electrics can get this type of kit sorted out if they decide to do so. My guess they will focus on 2017 sales first.
The other issue is cost. Is it worth it to do this? If these components were to be $3000-$3500 to upgrade the drive system, it doesn't necessarily make an older bike worth $3k more when you go to sell it. In fact definitely not. The total price differential in the end is probably very similar trading in the 2016 SR taking a loss now and getting a 2017 SR with all those components already, and especially the stronger motor shaft design. Also you can get a 2017 with a powertank with 1/2 kilowatt hour more capacity now. I know you ride all over North Carolina (I went to NC State in Raleigh and so each time you post I know exactly where you are talking about) and so I know the extra range you get even though just a little will be worth it to someone like you, and perhaps let your VStrom perhaps retire from service for good.
You could always try to sell your old powertank and buy a new one too, but again, the loss and effort in doing this might financially even be a loss when you consider everything, vs just trading it in on a new 2017 Zero SR with everything on it already.
You seem to have been a real good customer of Team Powersports, talk to them and see if they can treat you real good and give them a used 2016 SR with PT to have on their sales floor as a used bike. Keep your Elcons and racking and everything of course for the new bike.
Let us know what TPS says about the upgrades, but my guess is it's going to be a no go for now. As a 2 time customer already they should appreciate your loyalty and try to make you happy with the power you want on a 2017 and hopefully make it financially similar to what the upgrades would cost plus the fact that in the end the 2017 will be worth more anyway vs a 2016 with those modifications.
The other option is to wait to see what 2018 has. Although at this point it is a whole year away. It all I guess depends on how much you enjoy faster acceleration and how important it is to you to have it each day for the next year. My guess is for most people the extra acceleration wouldn't be worth it and upgrading every 2-3 years is the normal cycle for most on this forum, but I know you are an electric motorcycle enthusiast going back almost 8 years now like me and so we have different priorities and value calculations that we justify than most do.
Good luck whichever path you choose Vinny!