This has been plaguing me for a while as well and its interesting to hear that this is intended behaviour. ( although it does make logical sense if the other blueprints are actually changed, though in most cases diff-ing the assets show no actual changes using the blueprint diff tool)
Does this mean you guys aren’t looking into this as an issue any more or is this different than the issue in these posts?
https://answers.unrealengine.com/questions/73933/perforce-constant-checkout.html
https://answers.unrealengine.com/questions/63697/do-blueprints-that-make-a-call-to-a-blueprint-inte.html