My 2cts:
In order to prevent from reinstalling every thing when upgrading and to forget to restore something in the home directory (the backup software doesn't save the subdirectories from other applications than those installed by default, for ex, gpe) I'd written my own, one to save the whole home directory and one to save the miscellaneous files modified in /etc (ip-up.local, minircS, fstab, etc).
I do not need to save /var/lib/install since this directory is on the flash, so protected from firmware upgrade.
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