From what I can make out on the credits they’e back together on this one
It’s still credited as a “Grant Naylor” production, but Rob Grant has nothing to do with it.
Have I missed anything important with the story between series 8 and 10?
No.
TBH, continuity in Red Dwarf has always made Doctor Who look consistent. Back story is fast ‘n’ loose, as evident when Rimmer had to explain about his successful brothers for the benefit of Americans new viewers, the rest of the crew appeared surprised when in actuality it’s been established canon since day one.
I find it best not to think about it too much, otherwise you start to be kept awake at night wondering how Lister managed to have his appendix out twice.