I haven't played since the new patch was introduced so let me know if they've included this, but one thing I think would be great is if we can actually get some insight into what our character's backstory is. As it stands they're basically a blank slate, and apparently we're going to find out more about our backstory as the narrative goes on, but I think that's the wrong way to go. From a roleplay perspective, if they're gonna give us a backstory, it would be great if we could define parts of it or even just have a way to get an insight into what's coming later. I think that would also help us feel invested in our character as well, since a lot of people seem to not care much for the custom PC as they stand.
Relating to this, I was thinking about why people are disatisfied with the custom character in comparison to various other examples of blank slate characters in games. In Pathfinder: Kingmaker for example, you definitely start as a blank slate and all you know about your character is that they're someone who would answer a call to try and establish a barony for yourself. I think the problem with BG3 is that we really have NOTHING to anchor our characters on in terms of who they were as people. They were vanished from wherever they happened to be, got implanted with a tadpole and then escaped. We have no in-story hook to build our character's backstories out from, no indicators of who they could have been. Sure we have the choices present at character creation, but I think those are different from in-game information.