Worked out by the game's own trait code: the boon's first copy at each rarity, then each Pom of Power level, which adds the same amount whatever the rarity and less each time.
Delay
Common
Rare
Epic
Heroic
Level 1
0.5
0.5
0.5
0.5
Level 2
1
1
1
1
Level 3
1.5
1.5
1.5
1.5
Level 5
2.5
2.5
2.5
2.5
Level 10
5
5
5
5
Each Pom adds 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5 (levels 2 to 10).
Common
Rare
Epic
Heroic
Delay at each level and rarity.Show the numbers
Level
Common
Rare
Epic
Heroic
1
0.5
0.5
0.5
0.5
2
1
1
1
1
3
1.5
1.5
1.5
1.5
4
2
2
2
2
5
2.5
2.5
2.5
2.5
6
3
3
3
3
7
3.5
3.5
3.5
3.5
8
4
4
4
4
9
4.5
4.5
4.5
4.5
10
5
5
5
5
Damage
Common
Rare
Epic
Heroic
Level 1
60%
65%
70%
75%
Level 2
80%
85%
90%
95%
Level 3
95%
100%
105%
110%
Level 5
110%
115%
120%
125%
Level 10
135%
140%
145%
150%
Each Pom adds 20%, 15%, 10%, 5%, 5%, 5%, 5%, 5%, 5% (levels 2 to 10).