I wasn't originally planning on writing a review for this expansion, but since Trent Oster came out begging people to write positive reviews I felt compelled to voice my opinion.
First, the 800 lbs. gorilla in the room is clearly the SJW aspects of the expansion. I am a social libertarian, I don't care what consenting adults do in their personal lifes. However even I find the obvious SJW push in this game to be jarring, out of place and pushing an agenda. One of the two writers of the game, Amber Scott, even said as much. Calling herself a SJW and saying she makes a concious effort of putting social justice elements into everything she does. Her body of work certainly shows this, both her writing for the Pathfinder RPG and this game is pushing it extensively. I don't mind realistic deptictions of people with non-standard sexualities, but this comes off as an attempt by Scott to feel good about herself and her extreme progressivism more than anything else. And the writing is so bad that I wonder whether or not she has ever met an actual homosexual or transgender person. The most obvious example is the transgender priest in your camp, you say "You have an interesting name", the answer is to the effect of "I used to be a man so I made this one up". It is in your face and jarring, no actual trans woman would act like this. Bottom line is if this kind of thing bothers you then avoid this game.
However it continues from there. The overall writing of the game is generally bad. The plot twist with the villain at the end is extremely obvious to anyone with a brain, and doubly so for anyone who has played the Icewind Dale series. In fact the obvious nature of the twist as well as the blatant Lawful Stupid acts of Caelar Argent, the paladin antagonist makes it unbelievable at best. How can someone with the ability to detect evil at will not realize that a person close to her with a sinister voice and pitch black eyes is not a good guy?
Beyond this the game is also extremely linear, you have generally very little choice in where to go and what to do. And once you continue on to the next chapter in the expansion you cannot backtrack. There also isn't a whole lot to do beyond the main quest, there are several large wilderness areas but besides pointless fights with trash mobs there is rarely anything to do in them. After seeing your millionth tree or exloring your 10th cave you get very tired of it.
Truly cringeworthy attempts at humor are also to be found. These attempts at levity just take you out of the game and mesh poorly with the humor that was in the original. The encounter with an obvious "hippie stoner" in a tavern early on and very modern jokes and references to other media, like for example Portal 2 is very jarring. I do not enjoy it when characters make references to "spaaaace".
The last problem is that the game fails to do what it set out to in the first place. This expansion, previously known as "Adventure Y", was meant to bridge the gap between Baldur's Gate 1 and 2, and to explain how the main character came to be in the hands of the BG2 villain and why the particular companions in there were with him. And you do indeed start out with your chosen group from the original in the expansion, but most of them just disappear within the first 30 minutes with no real explanation. You are then saddled with an extremely narrow selection of characters to choose from. Token attempts at mentioning things to come are made, but the finale of the expansion, the villains you have defeated and the power you have gained just makes it seem ridiculous that a band of rogues working for the BG2 villain would be able to capture someone like you. And the reason why you are with the people you are in the beginning of BG2 makes no sense, they simply show up at the last moment for no apparent reason, regardless if you were antagonistic towards them the whole game or simply ignored them and didn't take them along.
Finally, the game is full of bugs. Serious bugs, gamebreaking bugs, that should never have made it through quality assurance. If you buy this now I hope you are comfortable with using console commands, because odds are good that you will have to. There are quests that can't be completed because a quest item didn't get registered. Achievements that won't fire, even knowing they existed it took me four or five attempts to earn some of them, others I have been completely unable to get even after multiple attempts. Other achievements fire too early or without even doing what is necessary to earn them. The biggest issue I've experienced, and seen numerous others face as well is a plot critical npc dying due to a bad event script without realizing it had happened and being unable to progress in the intended manner. Something as serious and common as this making it into the final release is just shameful.
After everything I've seen I can only say to Beamdog, don't make Baldur's Gate 3. Pass it on to Obsidian Entertainment or some other competent developer, fix the issues with the game, walk back you SJW agenda, then issue an apology for all of it. Hang you head in shame Trent Oster, begging for positive reviews you haven't earned is shameful.
Final verdict: Mediocre, 4/10 points.
TL;DR: Bad writing, bad agenda pushing, linear story and tons of bugs. Do not recommend.
