Something I also mentioned on twitter to play_pso2, but I wanted to share it here too. One thing I hope to see in the Story Quests for NGS is potentially a battle where we get to play as an NPC; with a limited set of PAs / Techs as to not overwhelm players. This would be more for dramatic effect or otherwise to fill in certain gaps of the story. The NPC you play as can also do chat bubbles as the battle progresses/etc. similar to auto chat for Partner Card NPCs.
It would be pretty easy for the developers to do this even in vanilla PSO2. Since they could put the player into the battle area during the cut-scene (no enemies present) then have them transform into that NPC during the cut-scene. The cut-scene ending would trigger the enemies to spawn, which is already easy for the developers to do, as they can do it at the end of loading screens and other cut-scenes already in PSO2.
This could work really, really well if you want to do more "Chapter EX" content like in Episode 5.
Honestly, what would floor me the most is if the first battle / tutorial story quest in NGS would be exactly that. Would be really good presentation and stage setting.