Thought this would be of interest. Taken from Safly & Sons Sporting Goods's Facebook page:
I've only shot pistols with manual safeties, so this appeals to me in theory (it's not an H&K, so I'm not actually interested). Not sure if people will end up riding the slide stop with this safety, looks like the raised "fence" around the slide stop might help with that, though that brings into question the availability of safety-compatible P320 grip modules.