If serious, you must have been adversely affected by a failed tubeless tire at somepoint.
serious! i've been riding the RR tracks and superfund / greenways around here in Edison and South Plainfield. there's so much CRAP everywhere, i've gotten 4 large punctures in my relatively new Surly Ednas (have had them on since october 2018, approx 700 miles so far).
every time i get a large puncture (three have been big nails / screws, one was huge thorn), there was a ton of sealant lost before i was able to get the plug in. so, i've started to travel with a 2 oz stans bottle to top off sealant mid-ride. however, taking out the valve core means the tire loses ALL of its air. this method can salvage some of that air and lessens the risk of having the bead come of the rim.
i've only used this thing once, in my garage, and to be honest, this past weekend, when riding with some friends, we had a chance to use it on my buddies bike, but we opted for valve core removal instead, so it's definitely a work in progress, but i think there's something there!
anyways, that's it! serious!, but seriously ridiculous, and did it just sort of to see if it works!