There may be a way to use the audiobook to expand some scenes.
For example, TFA has more Snoke dialogue and exposition about his motivations and character, used here to expand a scene where he talks to Kylo:
https://www.youtube.com/watch?v=LP-hJQyHpV8
Perhaps a similar idea can be used with TLJ.
Speaking of voiceovers, I believe the Disney Infinities video game line uses some voice actors from TFA. There may be some sources of dialogue there too.
On a different note, perhaps there would be a way to combine some of the dialogue from the Phasma deleted scene with the current scene. The unfinished scene’s SFX make it hard to use, but maybe some splicing could make it work.