In order for the tubeless rim to keep the air even without a tube, you need good rim tape and sealant as well as the right valves. DT Swiss has brought some made of aluminum onto the market, which in my experience work extremely well. Due to the conical round rubber seal, hand tightening with the plastic wing nut is sufficient and the air stays in. If you keep losing the valve key to unscrew the Presta-Insert, it is integrated into the otherwise superfluous valve cap - when sealant has to be refilled. The continuous aluminum shaft is also a few grams lighter than brass models. That's not a lot of mass, but it's located where it bothers the most and tends to cause an imbalance: rotating on the outside of the rim.
There are five sizes so you don't even have to think about extensions where the air would have another gap to escape. So pay attention to the right rim height.
Attention: The price is per piece, but most bikes need two of them. Sometimes different at the front than at the back.