-A more in-depth quest log or journal would be better. I would like the quests and their sub-quests to be more clearly laid out and distinguished from each other. And maybe more of a journal format? With notes based on if we passed History rolls, or Arcana rolls, or Religion rolls, or Perception rolls, etc. So each quest feels like our party is actively attending to it even in the journal, learning about what could be happening, and providing lore to make it a bit deeper.
-Meals are more than the sum of their parts. Maybe put a cooking pot in camp (like Breath of the Wild) where we can combine certain food items with low supply count into a meal with a higher supply count. On the other hand, make it optional because I know lots of people skip the cooking in RPGs (like Skyrim). It would make Gale's dialogue about stew MUCH better.
-Faction membership? Maybe doing a lot of quests for a certain faction can unlock a camp follower, or certain unique dialogue, or a special tag, or the ire of enemy factions, or allies in later acts or just recognition of membership from NPCs. Doing quests for Spaw upgrades your title several times. It would be nice if that meant something. Maybe you can get [Myconid Ally] or [Friend of Spaw] or [Life Chanter] tags? Doing a bunch of Druid Grove quests could earn [Friend/Ally of Silvanus] or [Druid Grove Ally] tag? Or the Zhentarim/Harpers/Absolute/Sharran/Gith/Devil Member or Ally tag?
-Occasional events or quests (even just one) which are class-specific. Perhaps a Sorcerer event about investigating/discovering innate ability or its history. Or a Wizard event involving study or acquiring study materials in a library. Or a Cleric event involving the deity, along with a Warlock event of the same type for a Patron (Don't even have to make a model if that's too much; a glowing light would probably suffice). A rogue event involving Thieve's Cant for a heist/assassination. An event to challenge the Paladin's oath. Etc, etc.
-An emphasis on consistency in worldbuilding, cosmology, and lore. Elsewhere I saw a discussion about how WOTC has been a bit flippant with the rules of the Realms... a consistent world makes for an immersive one.
-If ropes are involved in verticality or combat, make it use a roll.
-Discourage metagaming? (Controversial, I know). Primarily let us act on *very specific knowledge* only if it has been determined that our character has access to such knowledge, either by roll, or by proficiency, or by background, or by class, or by preceding quests. I think this is already being done for the most part (I noticed you can only grant blood for a certain sword if you know about said sword), but carry that attitude everywhere. Metagaming breaks immersion in tabletop anyway.
-More hidden areas. And hidden areas inside of hidden areas. And hidden areas inside of those. Make me feel like an explorer delving into places I am not meant to be. I like that it's a bit harder to find the Festering Cove, or that the Fetid Bog involves an illusion, or that a certain house in a certain village has a big basement, or that the Ancient Temple after the Grymforge seems to be a new hidden area.