Do we know if leakage is currently under test?

This test is poorly designed for .lan because the opposite problem is more likely: that many people using .lan will have any resolution attempts swallowed by their routers. This is certainly true for OpenWrt and GL.iNet. It may be true for Unifi AmpliFi, which reserves .lan by default. It's potentially true for other vendors when .lan is configured as the local domain (which many online guides suggest people do).