I'm afraid we don't want to add a "full exclusion" option into that toaster - that goes against its idea (on contrary, making all exclusions hash-based would make more sense to me). Similarly, we don't wanna add that option into a regular detection toaster, even though it has been asked many times. Having that option in the toaster makes it easy to either misclick, or to add the exclusion because the user "thinks" the file is safe. In a sense, having to go to the settings and enter the exclusion manually is a "filter", making it harder for completely-non-technical users to do what they probably shouldn't.
Yes, I admit in your case it doesn't work very well - but you're a special case, and making it better for you would make it more dangerous for most of the other users.
While I'm happy you like the hardened mode, a developer's machine really isn't the expected environment.
I guess a possible solution would be to make it possible to enter a wildcarded exclusion for Hardened mode only (i.e. that exclusion wouldn't apply to shields or scans)... maybe that happens one day if the exclusion-related interface is reworked.