@volblob
As far as I know we have no plan to provide Elektron SDK C++ libraries build with Visual Studio 2017.
However according to the following blog on MSDN
https://blogs.msdn.microsoft.com/vcblog/2017/03/07/binary-compatibility-and-pain-free-upgrade-why-moving-to-visual-studio-2017-is-almost-too-easy/
I think you should be able to use Elektron SDK C++ libraries for VS2015 with VS2017. This is because VC Runtime in MSVC 2017 is binary compatible with 2015. Loading your C++ projects targeting an older C++ toolset inside Visual Studio 2017 does not change your project. Thus if you have a library built with the v140 platform toolset, that binary and your code consuming it will continue to work even if you built your code with the v141 MSVC toolset.
I forgot that Elektron SDK is open source, and can therefore just build a 2017 version myself.