Rpg gameplay wise, Byvernia really does feel particularly wasted, not counting bubblelord being gone. For the longest time, and even for some time in game now she's incredibly deadly, she's half baked but you can see glimpses of her lore and weird banging dragon stuff, the tsundere attitude, unique fighting style with chained weapons and fire traps. She's far better party material than Vivianne who just seems like a kooky shopkeeper you might be familiar with. Viv might be interesting if she turns out to be a "Baba Yaga" like some people were speculating or like Melisandre from got, but just seems like a generic kooky horny witch, and most likely will remain so.
With her replacing Berwyn and the mouse thief that "missed the deadline", the party's incredibly awkward now. Base classes there's cait, healer/mage, brint/brienne, dual wield fighter, etheryn, who with the Alissa's castle upgrades is currently the most mandatory member, archer/healer/summoner and they buffed her damage a ton so she doesn't suffer in any area and has a ton of upgrades, quintillus, different flavor black mage, arona, barbarian "sword n board" fighter, atugia, sword n board fighter with spell, azyrran, sword n board fighter with spell, kiyoko, different flavor black mage, agni, weird bard without much healing so borderline useless imo, and vivianne, another weird bard that the player or kits do better. No summoner focused member like Berwyn, no melee and/or dedicated thief, 1 or 2 men, too much overlap.
It doesn't seem like there was much thought in the party design, the class kits can be fun but imo they still should have had each party member be more unique from the get go. Probably should have stuck with just 7 at most for that reason. Kits are nice if you really like someone/their kink but you already have their class, but the default characters shouldnt overlap so hard when basic character types aren't even in. Also, at this time, atugia has minimal content besides taking her along for lore dumps in certain areas, if you're locked in as male and masculine you go from being given flowers and romanced directly to losing out on most of azyrrans content for new hotness, kiyoko has been benched now for kinu so she just follows you and literally makes sandwiches when tobs isn't writing her as progressively more abusive and horrible, agni sits off in a cave and feels far too blatantly a writer soapbox instead of a immortal who's seen things, Viviane is a recruitable shopkeeper who most likely was just added as an emergency response to not have a large removal with nothing to replace it (Berwyn party>npc status).
Player satisfaction wise, obviously people don't like cait for various reasons, brint is liked pretty good but has a bit too much stuff that's ntrish or similar to caits hopping anything that moves, he's always written as bigger and better regardless of if PC has the magnum dongTM, deluxe model, with Olympic pools in reserve and years of fertility magic, etheryn was liked a long time but plot and preferences seem awfully sussy and like alypia is just writing her fanfic and forcing irl gender politics and "what, are you phobic?" stuff instead of letting the player just have options, quin isn't likeable and his content to make him more was forced and too late, him and takahiro both feel written as main characters you observe or as undeserved "superiors", arona is either a hardcore ntr villain or a pushover, no middle ground dommy orc mommy, az like said before imo is gender locked or at least "uh yes, I'm very very female, yes, can I come in now please I've been outside in the rain waiting for you to finish", atugia was hype AF and now just nothing really, kiyoko is like the iceberg meme of getting worse. Brienne begins devoted to mc with a bit of prior history of friendship, gets turbohorny for mc exclusively, and fills most vanilla-ish kinks and consistently gets more wholesome vanilla-ish content. She's popular because she's the ice cream that gets sprinkles and chocolate while the others are some combination of, empty tub, watching someone else eat your ice cream, having someone else come up and pour an unknown substance all over it, finding out halfway through it has an ingredient you're allergic to, having someone steal your ice cream and give you a soda instead, ice cream boys aren't allowed to eat, vegan sugar free ice cream that tastes like tofu, someone saying they love you and giving you ice cream that has slobber and teeth marks in it, or finding a tub left outside and thinking "wow I bet that would have been tasty"