Wasn't near Tahoe myself but I'm based in Durham UK so obviously not, but I'm curious whether anyone captured any thermal imaging or even just standard video footage from that night. The reason I ask is that hovering lights behave very differently depending on what you're looking at, and lake environments specifically can produce some genuinely odd atmospheric layering effects that cause distant light sources to appear stationary when they're actually moving slowly.
That said I don't want to immediately jump to a mundane explanation because I've documented a few things over the years that looked explainable on paper but weren't when you dug into the data properly.
Was the light perfectly static or did it drift slightly? And what was the approximate elevation relative to the treeline - that detail matters more than people realise when you're trying to rule out drone activity vs something else. Anyone who was actually there and has even rough compass bearing notes, that would help narrow things down considerably.