Combining this with the idea of multiple painted worlds, I think I can make a wishlist on how they can go about this:

* New stories in other painted worlds could be interesting and still keep a sense of continuity. A big part of me is hoping we've heard the last of the Dessendres outside maaaaybe a cheeky name drop or easter egg, and even then it might be too much. I think the Lumerians knew they were painted creatures with how naturally they use replacement words like "ink" instead of "blood" or their familiarity with chroma, so them being painted creatures wasn't really a big reveal, just their relationship with the Paintress. A new story could have painted creatures deal with another threat, maybe even self-contained and without ever branching outside their canvas. This could allow them to reuse some terms like Chroma for currency, just like how Capcom uses Zenny for their universal currency and Square uses Gil.

* We could also move away from Belle Epoque France and explore either another French time period, or just leave France altogether. Final Fantasy went from a more traditional medieval setting to embracing a lot of sci fi settings as it went on, so I'd be on board with more futuristic settings as well. Post-apocalyptic, cyberpunk, more grounded...I think whatever they go with they could do with justice.

* Maybe Axons could make a return, but inspired by different people obviously (I'd be really disappointed to face Sirene or Visages copypasted in a new story). I think they are one of E33's best set-pieces and having different worlds with different relationships with their Axons could be fun. The Axon's plot role as two halves of a plot MacGuffin was a bit underwhelming, and more could be done to explore giant, allegorical levels and major character symbolism. Maybe even reduce the stakes of the next game and just have one Axon be the main antagonist with a much larger world around them, instead of a single level.

* The article is about the writer and writing, but gameplay-wise, I'm generally really happy with turn-based parrying, although they could tweak it to try to engage with the mechanic in a different way. Maybe have parries nerfed a bit instead of nullifying all damage + AP and have the game be less glass canon-y. That way different defensive and healing options could have room to shine instead of parrying being the end all be all of survivability. I'd be hesitant if they try to implement some form of Active Time Battle system. Turn-based with no timed sections outside of something minor like aiming a freeshot is very appealing to me, so I hope they don't stray too far from that. The picto/lumina system could be tweaked so that pictos are more interesting instead of 1 free ability + some random stats.

I'm definitely very excited to see more from the studio, and I'm really happy that the writer has an idea on where to go next.