This is a fair point. I would hate spamming any maintainer. Most of these contributions will happen after the students have completed their curriculum and done 1-2 concept designs. [Apologies if I did not make it clear that I am just trying to replace the redesign projects -- not the new concept design]
At the same time, if I fork any repo of my choice -- I don't think we'll necessary work on the most important aspects. Reducing the chances of the design getting incorporated or the students getting any objective feedback to improve things.
But when it came to large complex codebase or problems that required critical thinking everything fell apart.