Though, honestly, it seems like you could save everyone's time and get similar results screening for university GPA > 3.8.
GPA's are meaningless now. Grade inflation, etc. Just like the adversity score that will be added to the SAT... making it meaningless... IQ tests are going to replace GPAs for hiring in general.
I don't see it as unpaid labor anymore than I would see the interview process itself as unpaid labor.
The idea is that you interview at some place that asks for a substantial take-home interview project. You do it. Afterwards, the project requirements and your solution are turned over to third party.
Then the next place you interview wants a project, too. You can point them at the third party and authorize release of your info to them. They can then see what that first company asked for, see what you provided, and if it covers the same kind of things that their project does they might then accept it instead of making you do another one.
'unreasonably arduous'- how would you define that. Really a few phone convos, a take home assignment and showing up for interview is unreasonably arduous for a diverse candidate?
This actually shows to me that the company is not willing to hire someone diverse without properly vetting them. Good for them.
It was an observation. I can't help if they were insulted.
So sure, diversity as long as you’ve got a spare day or three to jump through their hoops. Doubt I’d see any parents or people over 30 in their diverse pool of people willing to work for free.
Edit: if this is your process please notify candidates at the outset.