In any case, Gatekeeper is mostly intended to save grandmas who are at risk of downloading random malware from the internet.
If you're a developer who is reasonably aware of how computers work you might as well disable Gatekeeper entirely. You're taking many times more risk every time you use Terminal.
Nowadays (as of Sequoia, I think), I find that I need to run `xattr -c Foo.app` to clear the “this was downloaded from the Internet” bit on the application bundle before I can right-click, “Open” it. Used to be that you only needed to do that with .apps extracted from zip archives, but it seems to apply to .apps copied out of disk images (DMGs) now, too.
For plenty of users, a button right there in the popup is almost the same as no Gatekeeper for most scenarios, but if we can handle it why not let us