I reckon this (dis)advantage is not very big for lower rated players using territory scoring on 19x19 boards.
In points, ranks on 19x19 are spaced by a full handicap stone, which corresponds to 2 times komi (~13 points), so the (dis)advantage of 0.5 points is about 4% of a rank.
Around 1d EGF, the value of a full handicap stone is about 100 Elo points, so for equally rated players of that level, this point (dis)advantage corresponds to about 4 Elo points shift, which corresponds to about 0.5 percentage points winrate shift away from 50%.
For equally rated DDK players (handicap stone value about 33 Elo points for EGF ranks), a 0.5 point (dis)advantage may correspond to about 0.2 percentage point winrate shift, and for pros (handicap stone value about 300 Elo points for EGF ranks) it may be about 1.7 pp.
At 9x9, when using 6 ranks per full handicap stone, 0.5 points may correspond to about 3.5 percentage point winrate shift for 1d level, about 1.2 pp for DDK level and about 10 pp for pro level.
With area scoring, the score resolution is about twice as coarse as with territory scoring, so you probably need to double the Elo shifts. In that case, using 7.5 instead of 7 komi may shift the winrate on 9x9 boards in white’s advantage by about 6.5 pp for 1d level, 2.1 pp for DDK level and about 19 pp for pro level.
So I think it is a good idea to account for a 0.5 point advantage in the rating system. It will make the rating system more accurate, especially for stronger players using area scoring on smaller boards.