I remember a few back then. Softride had a suspension stem too and Girvin too. I recall seeing them first on bikes used in the Paris-Roubaix.
I had a Softride tri bike and they came out with a mountain bike and they used their suspension stem on it, along with the suspension beam the rider was suspended but their mountain bike line disappeared pretty quickly. Suspending the rider is only for comfort, it won't do much for better control of the bike and handling.
I was wondering if anyone had tried a suspension stem on their gravel bike and whether they noticed more comfort, less fatgiue, anything good, anything bad. Double bar tape might be just as effective?