I shudder to think of the difficulty in maintaining phase coherence at optical wavelengths for the baselines they mention in this article.
This is the mentioned paper from december 2020 about hour-long optical storage (by Chaun-Feng Li et al.):
https://arxiv.org/abs/2012.14605
(Earlier article from 2015 about this storage technique: https://newatlas.com/quantum-encryption-storage-drive/35553/ )
Still other work to be done, and worrying about what happens in the fibre optics, but it is becoming possible, especially if the coherence does not need to be long lived.