That doesn't quite catch the whole motive behiind RLO though. The main point was to shift the cresting points where the exp/lv goes up (every 5 levels). . .so that -2 kobold won't need to double EXP cost per level until 8, where a human does at 6. . .and all races become equal once all have crossed the 50k per level line.
It advises that a -2 kobold playing with humans of 1st level should probably be around 3rd to balance it out, but you could just start them off at 1st, and they'll get their benefit off of that delayes exp crest later.
The rule on level adjustment is more important in the reverse direction, with stronger than human races. (A party of 1st level humans will likely be both literally and figuratively in the shadow of a 1st level Cloud Giant.)