I think I'll throw out some dice rolls while I consider my options.
STR: 3d8 ⇒ (2, 2, 7) = 11
DEX: 3d8 ⇒ (1, 4, 5) = 10
CON: 3d8 ⇒ (1, 7, 7) = 15
INT: 3d8 ⇒ (8, 1, 1) = 10
WIS: 3d8 ⇒ (6, 2, 6) = 14
CHA: 3d8 ⇒ (2, 5, 8) = 15
EDIT: Rerolling because the first set was terrible.
STR: 3d8 ⇒ (4, 1, 7) = 12
DEX: 3d8 ⇒ (3, 2, 4) = 9
CON: 3d8 ⇒ (1, 2, 3) = 6
INT: 3d8 ⇒ (2, 8, 2) = 12
WIS: 3d8 ⇒ (5, 8, 2) = 15
CHA: 3d8 ⇒ (4, 6, 4) = 14
And it was somehow worse. I am struggling to think of what I could do with either of those sets.