Relinquishing copyright does not imply any of the labor you're suggesting. It's the opposite: you're just committing not to perform the labor of pursuing legal

Relinquishing copyright does not imply any of the labor you're suggesting. It's the opposite: you're just committing not to perform the labor of pursuing legal action against someone who does digitize and freely distribute the work. Anna's Archive, for one, would be more than happy to host at no cost to the author.