Your finished archive
Does the archive work in Apple Photos, Google Photos and iCloud?
Yes. Because dates and positions are written back as ordinary EXIF data, the memories land in the right place in the timeline and on the map when you import them.
Yes. We write dates and positions back as standard EXIF data, which is exactly what those apps read when they sort a library.
In practice that means a snap from the summer of 2019 lands in July 2019 in the timeline, and in the right place on the map if the position was included in the export. Not in a lump on the day you imported, which is what happens if you put the raw export in directly.
We use no formats of our own and require no app to read the archive. These are ordinary JPEG and MP4 files. They work just as well in Apple Photos, Google Photos, iCloud, Windows File Explorer, on an external hard drive, or in whatever program you switch to in five years. That is deliberate: an archive that requires a particular app is not really yours.
A practical tip when importing: bring the archive in as one go rather than folder by folder. Photo apps handle one large import better than many small ones, and you avoid duplicates.
If you have already imported the raw export once and thrown your library out of order, delete those files first, then import the processed archive. Otherwise both versions stay there and you have two of everything, half of it with the wrong date.
One small thing worth knowing about time zones: a snap taken abroad gets the right time relative to where it was taken, provided the export contains GPS. Without location data we go by the time as it stands in the export and invent no adjustment.