Low elastic travel means the binding has minimal give before it releases your boot. Think of it like a spring with less stretch — when a sudden force hits, the binding releases sooner rather than absorbing that shock. This is very common in pin-tech and ultralight touring bindings because the simpler, lighter mechanism simply can't flex as much.
The trade-off is real: in choppy snow, at speed, or landing drops, you're more likely to experience an inadvertent release (also called a pre-release). The binding lets go before you intended because it can't absorb that momentary force. If you're skiing aggressive backcountry lines or mixing resort and touring days, this can be frustrating or even dangerous.
Low elastic travel makes the most sense for skimo racing and mellow ski mountaineering where every gram counts and you're not pushing hard in rough terrain. If you want to charge in the backcountry, consider a hybrid binding with more elastic travel, even with the weight penalty.