Fallen leaves, best if damp, kicked strategically, make very effectively seal for the edges. Needle-duff could also work.

Obviously in a very high wind, or above treeline, this would not work.

Best is snow, which creates a bomb-proof seal against all weather.

In a pinch, rocks and logs work well, but may cause undue wear.

With minor resourcefulness by user, the Hex-3 is quite weather-proof and useful in any ordinarily foul 4-season conditions. Caveat: the seams need sealing, contrary to manufacturer's claim of a few years ago.

Am unfamiliar with Sierra Designs model. The Black Diamond "BetaMid" probably provides greater square feet per pound than the GoLight Hex. The BD model may have greater issues with lack of headroom per square foot. In theory it has less wind resistance, though in practice, is trivial.

I strongly believe the Hex-3 is too small for the smallest available wood stove, unless perhaps it were for use by a single person plus the stove. It would need extensive modification for stove pipe.