Wow, that… actually did it!
I had actually tried writing that in my code at one point, but I didn’t bother trying to compile because Visual Studio threw a preemptive error warning at me for it. Which I should’ve known to test anyway because it’s not the first false-positive I’ve gotten from IntelliSense not really understanding what’s going on with interfaces 
Thanks for your help though! Guess the moral here is I need to start thinking about throwing down some cash for ReSharper or something 