I don't think there is any equipment bought from the West that they could be used against - unless you include Turkey as being Western as they supplied drones?
I think you're right, so far it there is the $200 million military package from the USA but that's just for anti-tank missiles. I guess USA wouldn't want to pit their heavy weapons against Russia even in a proxy war scenario. They've been doing everything they can to keep the F-35 away from the S-400, because of the stealth tech, but the same might apply to their other technologies.