I really want to stress this too. I was playing EA solo and my friends didn't want to (due to many bad experiences in various other EA games). Now more and more of my friends started playing BG3 since release but we do not play together exactly because of this... due to everyday stressfull life, we do not have the time to always organize a time to play together, so ideally we would want to play a solo campaign and join up if another of my friends has time. but as the system is right now, this breaks your current save game and you need to revert. There is an unofficial workaround, but doing that you never know what else you might ruin in the files along the way.
This is especially frustrating when you encounter such great moments in the game, that you would like to share with friends on your first play through.
So I fully support the suggestions from Skallenia 1 to 1. at least a simple add and throw out option of the friend made char so that the host can easily continue solo for a while, and the friend can join in later again and taking control of his already made Char from before.
a nice to have option would also be (and this was possible I believe in BG2 and NWN) export your char file, so that you could take it to another game and continue his/her path of adventuring in another campaign.
