US courts giving insane leeway to corporations in what a contract can include has nothing to do with whether rights are defined absolutely or not. The exact same scenario could play out if the voluntarily waived rights were reasonably limited rather than unlimited.
> could play out if the voluntarily waived rights were reasonably limited rather than unlimited
My point revolves around the unlimitedness of the other right that is being used to override the first right in question. A large part of that "insane leeway" is exactly due to the corpos' rights being taken as unlimited/absolute - note how the argument in Pruneyard was trying to use property rights to override free speech rights.
But sure, rather than tweaking the conception of rights, we could instead target reform at reigning in the "rights" of corpos - they are merely whole-cloth creations of government, after all. But I suspect we'd still hit corner cases with sufficient power imbalances between individuals (say a small-time landlord and their tenant, with the landlord attempting to curtail the tenant's speech).