I don't know, I understand the advice and I guess that's probably one of the reasons Loop (https://loopkit.github.io/loopdocs/) is not on the App Store. If they had turned their project into another data-logging platform we wouldn't have commercial closed loop systems.

Thanks for the link. Yep - exactly, they took a leap, but importantly didn't release a full product / package on the App Store, or charge for features. This falls much more into a grey area, but is clearly DIY, and demonstrates demand/need for the commercial / regulated systems.

Especially when the problematic features are charged for, it gives the recommendations / suggestions an air of legitimacy which could be dangerous.