You can correct for half a stone and the EGF does this.
For example, say you’re a 7d EGF playing against a 6d EGF on even. The difference between those players is 100 GoR, which is about 200 Elo in that range, which means the 7d is expected to win 75% of the games.
When the 6d gets black without komi, it only compensates for half a rank. So the difference is still 50 GoR, which is about 100 Elo in that range, which means the 7d is still expected to win 65% of the games.
Another example: a 19k plays against a 20k. On even, the difference between these players is 100 GoR, which is about 35 Elo at than range, which means the 19k is expected to win 55% of the games.
When the 20k gets black without komi, it compensates for only half a rank. So the difference is still 50 GoR, which is about 17.5 Elo in that range, which means the 19k is still expected to win 52.5% of the games.
Same again but now for 2d vs 1d (100 GoR is about 100 Elo in that range):
even game (100 Elo) => 65%
no komi (50 Elo) => 57%