Why is the size larger in Migration Assistant than in Finder or `du -sh`?

Running Migration Assistant to transfer my files to new mac. Going from M1 Max (macOS 12.6) to M4 Max. Both Finder (size and size on disk) and du -sh of the home directory reports around 500GB, which is exactly what I have left after transferring applications and other files. I also made sure to move sparse files, like Parallels, OneDrive, UTM directory to a temporary user directory since these had caused problems in the past. However, it still shows a total of 1.04TB for Library/ when is under 200GB, other files and folders have relatively accurate size. What might be going on? Currently I've just manually copied over some application preferences / data / licenses, and some keychain items (but not all - I had to enter the password for each item and I have about 200) which works but is painfully slow. What can I try next?