Yes, but the main problem is not exFAT—it’s that Lightroom stores file paths, and macOS and Windows use different path formats. A catalog created on one OS may not automatically find the originals on the other.

Two practical options were suggested:

1. Use Smart Previews. You can edit on either platform using Smart Previews, then export from the same platform that originally imported or linked the photos.
2. Try using the same network-style path on both systems, such as a UNC path (for example, a shared folder accessed as \localhost\sharename). If Lightroom sees the images through the same path on both platforms, it may avoid repeated relinking.

If you continue using direct local drive paths, you’ll likely have to update or relink folders when switching OSes. So while cross-platform use is possible, it works best with Smart Previews or a consistent shared-path workaround.