I mean not Celestia Origin itself, I mean if any of the textures can be modified for use in Space Engine. Remember when before the Steam edition, Venus', Uranus and its moons', and Neptune's textures were all based on Bjorn Jonsson's, James Hastings-Trew's, Ivan Rivera's, and David Seal's textures, respectively?
Most of the things I've seen in there are already in use by Space Engine
For example, Neptune's textures show in Celestia Origin are the same that's being used in Space Engine. SnowfallTheCat made it
and also I've seen no source link to the source material in that addon, which is to me a bad thing to do