I agree — very strongly. Sébastien and Paolo have expressed the reasons well.
I think this should definitely not be part of the SPP at launch time — unless it’s included merely as a suggestion of a possible process that individual projects could consider adopting if they want.
I don’t think “require C4, but with individual clauses we don’t like removed or amended” is an improvement on “require C4”. The problem here is requiring something contentious and complicated. I think the platform should not do this. Fiddiling with the details of what’s required doesn’t fix that.