Hi Jason,
Thank you for the question!
Unfortunately, as far as I know, there is no way to import library from Twinmotion 2019 to 2020. Since Twinmotion is developed by Epic Games, I would suggest sharing your request directly to Twinmotion support here:
https://twinmotionhelp.epicgames.com/s/
Thank you very much for your understanding!
Best regards,
Minh
Minh Nguyen
Technical Support Engineer
GRAPHISOFT