I hate to say this but I just got past Freedom Nadd's tomb, did you ever try just... walking through the door? Like I know that sounds bad but I mean literally running into the door? It stayed closed for me but it had no collision and I loaded into Dxun fine.
Thank you for the installation guide, it didn't solve my own problem but I'll leave what worked for me (so far) here for any future users.
I installed TJM manually onto the Aspyr patch version on Steam, along with the wonderful 3C-FD Patcher by J. The mod launches and runs fine on the modern version to my knowledge but to fix the dialogue you gotta play around with it; imo it's worth it for the qol that the Aspyr patch + 3D-FD patch provide. Go into the TJM part 2 installation ZIP, >StreamVoice>GBL. You'll see a bunch of folders with .wav files inside; you need to convert all of them to .mp3. There's about 3000 of them and it took me about 15-25 minutes of work with Audacity. Once you do that, use JCarter's SithCodec to encode the .mp3s into the VO format, then put the encoded files back into their GBL folders. Keep all the folders under GBL in order (IE, keep all the "bast.mp3/wav" files in the bast file) and then in your Kotor 2 directory, pop the new Streamvoice folder into your Kotor 2 directory, overwrite the old files, and it should work a-okay.
Hope this helps someone in the future.
Did you end up getting this working? I've been having a ton of trouble getting the mod going both on the Aspyr patch and on the legacy beta. Help would be greatly appreciated