Yeah sorry we should have standardized them a bit more beforehand. Hopefully I can get some input from devs this time and we can find a better default layout for default.
I would probably do WASD vs Arrow keys, though not sure about A and B. I guess A and B could stay as space/alt for player one, player two could maybe have 0 and . on the keypad? Though not everyone has a keypad. Maybe ctrl/shift for arrow keys?
Another keypad option is 8/4/6/2, and maybe 0 and . for A and B.
Your best bet it to probably support multiple layouts, or even input configuration.