As much as I agree with this, buying off the shelf things, especially on the extremes of "very niche" (ok this kinda how's under your "hobbyist design" or "so g

As much as I agree with this, buying off the shelf things, especially on the extremes of "very niche" (ok this kinda how's under your "hobbyist design" or "so general there are hundreds of knockoff versions with various cost cutting measures", there is no guarantee that they have thought of all (or any) of the required safety measures... Check out Big Clive on YouTube if you haven't already, and aren't afraid of knowing about all the different ways products skimp on safety.