It seems that at time of writing, Excel's dependency tracking functionality is only able to track spill arrays as if they were any other array, and so it cannot differentiate between a calculation that is element-wise and one that operates on the whole array input argument(s).
The only viable solutions for tasks where one column needs to take outputs from another column as input are:
Use a helper row to hold the true input and then use an external (to Excel's native formulae) means to copy the reference output to the input cell. This could be VBA or, in the worst possible case, a user input with visual feedback if the value is out of date.
Stack multiple (optional) calculations into a single column. So in my real-world example, I may just design for a maximum number of sequential turbine stages and stack those calculations into each column.