Sequential inheritance isn't overriding previously inherited keys

[srithon]

Minimal breaking example

[configuration]
input = "..."
output-name = "..."
output-pre-command = "..."
cmp-seq = 'rctrl'
cmp-seq-delay = 5
fallthrough = true
allow-cmd = true
starting-layer = base

[base]
[[keys]]
1 = (tap-hold '1' '2')

[numerics]
[[keys]]
1 = '1'
2 = '2'

[alt]
parent = { base, numerics }
[[keys]]

Expected Output: alt maps 1 to 1 and 2 to 2, overriding the inherited mapping from base with the one from numerics.

Actual Output: alt maps 1 to (tap-hold '1' '2').