the gap between humans and other metatypes at character creation is a huge hole that needs to be patched up at some point.
Humans are at disadvantage, yes. But the gap is not 'huge'.
Compensating humans with 10 extra customization karma will be [more than] sufficient.
Or counting racial positive qualities towards the maximum six positive qualities.
Take any build where Metatype isn't A or B. Got one? Switch one thing: if it's a human, make it a meta. If it's a meta, make it a human. Observe what happens. The advantages for metas vs humans is that simple.
I just made an Edge 5 mundane human with Exceptional Attribute (Agility) and Low Light vision (plus 4 other Positive Qualities as six is the max).
When I switched to Elf I still had 5 Edge (and I was also allowed to keep any combination of mental and physical attributes I could have chosen as human), but I now got both Low Light Vision and Exceptional Attribute for free (worth 6 + 12 karma). Not only that, I am now also allowed to spend the newly earned 20 karma on two additional positive qualities beyond what I was allowed to pick as human....
To be fair, as Human I also got a rank of Exceptional Attribute (Edge) that I might or might not get use for later in my career (post chargen). But then again, as Elf I instead got two 'ranks' of Exceptional Attribute (Charisma) so I am not sure the edge thing should be counted as an advantage in this case (also during encounters your total Edge is capped at 7 no matter if you go Human or Elf, which kinda diminish the value of having an Edge rating higher than 6).