Thank you!
While 20 may be too much, I don’t believe it would because according to these stats posted by Jeff: Competitive Mode Tier Distribution (a few years ago, the distribution should still be very similar) we can see that the gold playerbase has roughly 30x as many players in it. This means that if GM has 3 avoid slots, to match the same ratio of avoid slots for gold, gold would have around 90 avoid slots (3 x 30). This sounds like too many, but the ratios appear to pan out.