I've seen Lotus Notes client installation's folder being migrated from Windows XP to Windows 7 then onto RHEL and finally onto macOS.
Suffice to say that all of the user settings were preserved and the data was readily usable on each platform. This happened over the span of 10 years.
Given the observation, I wonder how many other applications with similar complexity would last even one migration, let alone rolling migration across 4 completely different platforms.
Once they introduced transactional logging (highly recommended for busy systems) there were a few more steps to the migration, but they are all well documented and surprisingly resilient.
I managed to migrate a few TB of email from a dying server and it handled mid migration crashes surprisingly well!
I think the domino stack was getting better while the notes client was losing the plot. Most people where I used to work were happiest with mobile clients connected via exchange active sync to the domino servers.
Suffice to say that all of the user settings were preserved and the data was readily usable on each platform. This happened over the span of 10 years.
Given the observation, I wonder how many other applications with similar complexity would last even one migration, let alone rolling migration across 4 completely different platforms.