Something like that will indicate whether the bundle has been injected successfully or not. However, once the bundle is injected it is hard to know if it has done it's job correctly inside of the Finder process.

In FinderOverride.m:87 there is a logging statement that the bundle emits when it thinks that the function override has worked successfully. You can see it show up in Console.app. Things have changed so much since I first wrote this that I wouldn't be surprised if things weren't quite working like they used to. I wish I had the time to give it the debugging justice it needs ;)