Skip if the two sequences to the right have different shapes: ߞߞߞ ߞߞߞ.
Test passes if the 5 N'Ko characters join, making the two boxes identical.

ߞߞߞߞߞ
ߞߞ‍‍ߞ‍‍ߞߞ

Assertion: Shaping is not broken across inline box boundaries for changes to colour in N'Ko.