It's nice to know that the LCS problem can be solved in O(n) space using the algorithm made by Hirschberg.
It's nice to know that quick-select can be done in O(n) worst-case (deterministic).
These "more efficient" implementations likely aren't as easy to understand/modify so I get that someone may intentionally choose the ones that you have here
My team just had to swap out the normal quick-select algorithm with the deterministic variant, so I will have to disagree with the general/unqualified claim "is actually not used in practice".
It's nice to know that the LCS problem can be solved in O(n) space using the algorithm made by Hirschberg.
It's nice to know that quick-select can be done in O(n) worst-case (deterministic).
These "more efficient" implementations likely aren't as easy to understand/modify so I get that someone may intentionally choose the ones that you have here