Thanks for the great post.This next one was the only “study” I could find reviewing the effectiveness of tourniquet use in the pre-hospital setting. Based on over 1100 limbs with tourniquets applied, the authors concluded that overwhelmingly tourniquet use was helpful and rarely led to permanent damage or amputation of the limb
As for published research, I think there's also a piece from late 2020 or very early 2021 - news of it came through to my advanced first aid / Stop the Bleed instructor (US Army TCCC trained) right in the middle of class in Jan 2021. He interrupted the class to share the good news.