B

In a different ecosystem with poor tooling, I've implemented similar test partitioning methods. Hand-rolling it also made it possible to create a more balanced partition, by using the previous CI run's test durations to inform the split.

That's pretty cool

This is making me think I shouldn't ever be using an action with the "version" as a tag...
I can see there being resistance to using the actual commit SHA, because the tags are the way it's designed to be used.