Your concern can easily be addressed by having a 100% tax on the value of land and then distributing this tax money through a citizen's dividend.

But this isn't all that related to the productivity dividend. That's more natural by setting banks to have a full reserve requirement. At that point new innovations would yield deflation, which would be harmful. The Fed would then have to step up and be the creator and distributor of new money. That money would then be the UBI, distributed equally to all.