Clamping dimensions aside, are all stems rated for all the cycling disciplines, especially in the MTB domain?
In other words, are stem manufacturers liable to guarantee their products to be safe to use on any bike, from XC to DH?
In the documentation coming with stems, I almost never see intended/certified usage for the product to be stated. Some web shops do list intended usage for stems on their product page, but I take those are recommendations.
It surely does not make practical sense to install an e.g. 100 mm carbon stem, clearly intended for an XC frame, on a modern gravity-oriented "Enduro" frame. But there is a range of stem lengths and types for which the intended/safe usage is not apparent from how just the product is sized or looks.
Is a random 31.8mm × 50 mm stem I've found in Decathlon safe to use on a bike with 170 mm of travel? What about stems usually found on commuter bikes?