When the heart rate monitor is switched off, there is no pain/tingling even if I wear it tight and this has been corroborated by many others in fitbit/apple watch forums.
But since, most of these cases are due to wearing it tight (or the manufacturers want to project it that way) the heart rate monitor issue is not getting enough attention.
I also switch from left to right. Maybe that makes a difference?
The other thing is that the two explanations are not mutually exclusive. Once you loosen it fully it moves around on your arm, which might move the harmful parts away from whatever is vulnerable.
Do we know what exactly causes the tingling? My left hand is still numb almost a week after I was first injured.
Although loosening might help you place heart rate monitor at a different place or avoid direct contact with skin; in my(our) experience switching off HR produced definitive results immediately.
The reason for why HR does this is speculative(I've covered in my blog), as long as the consumers demand strong action from the manufacturers we're not going to find the reason.
On a serious note, Doesn't insurance companies already partner with fitness monitors? They claim to provide incentives for good health by offering discounts in premium but then again it could also mean higher premium if any health issues are detected by these fitness monitors irrespective of its accuracy.
[1]https://abishekmuthian.com/my-experience-with-fitbit-charge-...
[2]https://abishekmuthian.com/insurers-are-putting-the-lives-of...