Yeah, my current character had dumped a bunch of karma into knowledge skills in SR5 that were lost in the conversion to Anarchy. Like most things in this game, I think the intent is for knowledge skills to be something that can be used flexibly based on how the group likes to play. LOG+LOG for an untrained test sounds reasonable. And if you want to roll for knowledge in general you could probably say that knowing a particular thing gives you 6 points in that, so roll LOG+6 for things on your list. Or you could break it down further and have knowledge ranks of say 3/6/9.
As a related criticism, my #1 wish for Anarchy is that the rulebook said "this is the default way to do things. However, you can also approach this thing via options A, B, or C, without unduly breaking the game." Some of this exists in the form of optional rules, but knowledge skills almost feel like an afterthought, some amps add dice while some add rerolls, etc, often with no explanation of why, when the explanation often is "all the ways work, do whatever sounds fun to you!"