SKS lists the Airspy as compatible for tubeless tires. It is possible for the sealant to clog the valve over time, but I think most modern sealants shouldn't have an issue.
The Airspy seems to be available on the SKS US website (sks-us.com/products/airspy-wheel-mounted-air-sensor-presta). If you're overseas you can find SKS dealers via their website www.sks-germany.com/en/service/shopfinder/.
Not so much while your riding, but the Airspy is very convenient before / after a ride to double check the air pressure without attaching a pump or gauge. You can even connect the Airspy to the SKS App or Garmin computers so you could check if your losing air while riding.
Why though? If you care about tire pressure that much, 40g is too much extra weight for you. If you don't care, you'll notice low tire pressure on the next ride anyway.
I partially agree, the Airspy is a bit too bulky and expensive to have a lot of appeal. However, you'd be surprised how easy it is to be ~20-30 psi off your desired pressure and still pass the simple visual or thumb check. Using a pressure gauge or floor pump before rides is more reliable then just looking or feeling a tire.
The idea is that you can quickly your tire pressure before you ride or get a phone notification if you get a leak. I expect this type of technology will become smaller and cheaper over time so that it could be directly integrated into wheels.
I use to think that also but I have been now using a competitors product for two years on my XC FS MTB and you would be surprised how much a 1 to 2 psi difference makes when riding hard and fast. And the greater level of traction in a down hill 30 mph of camber turn is when your tire pressures are dialed in. I have also seen TP fluctuate 5 psi just from driving 120 miles to a ride location due to the air temp change between the two locations. If you can afford them they are well worth it. I have mine set to flash "red" of the pressure is off by just one psi. Just pump up the tire until it flashes green and then I know my pressure is set. But hey this is just me so many people dont even check their shocks or their forks before a ride....they just like to bitch about why something goes wrong. These are a bit bulky compared to what I have but perhaps I put these on the MTB and the others on the Gravel bike....all will connect to the Garmin 1030 Plus which is ideal for me.