Repair outside the Photos library
Keep the original Takeout ZIPs and create a separate repaired output folder. Do not point a metadata tool at the internal contents of an Apple Photos library package.
A portable output can be inspected with ordinary file and metadata tools before Apple Photos creates its own library records.
Check dates and locations Apple Photos displays
Apple documents that the Photos Info window can show the date and time captured, camera details and location stored with a photo or video. Inspect representative repaired files with Command-I after a small import.
Test dates edited in Google Photos, screenshots and videos separately because their useful source fields can differ from camera JPEGs.
Keep Live Photo resources together
A Live Photo normally relies on a still image and short video sharing a content identifier. Keep paired HEIC/JPEG and MOV resources in the same organized directory and do not rename one independently before import.
When both original identifiers are missing, filenames alone do not justify inventing a new Apple MakerNote identifier. Preserve the resources and report the limit.
Avoid duplicate album copies
Takeout album folders may repeat exact media. Reconcile identical hashes while retaining album relationships before importing, otherwise Apple Photos can receive several physical copies of the same bytes.
Edited or merely similar images should remain separate for manual review.
Run a staged import
Import a representative set first and inspect dates, timezones, locations, descriptions, videos and Live Photos. Only then import the complete verified output.
Keep the repair report and original ZIPs until the Apple Photos library has its own independent backup.