The below might be handy. The result file contains some brief results including a run time.
Remote URL can feed Duplicati.CommandLine.BackendTool.exe, if destination requires it.
Sample result file stats. Messages follow later:
DeletedFiles: 0
DeletedFolders: 0
ModifiedFiles: 0
ExaminedFiles: 1
OpenedFiles: 0
AddedFiles: 0
SizeOfModifiedFiles: 0
SizeOfAddedFiles: 0
SizeOfExaminedFiles: 14
SizeOfOpenedFiles: 0
NotProcessedFiles: 0
AddedFolders: 0
TooLargeFiles: 0
FilesWithError: 0
ModifiedFolders: 0
ModifiedSymlinks: 0
AddedSymlinks: 0
DeletedSymlinks: 0
PartialBackup: False
Dryrun: False
MainOperation: Backup
ParsedResult: Success
Version: 2.0.5.111 (2.0.5.111_canary_2020-09-26)
EndTime: 12/20/2020 7:11:29 PM (1608509489)
BeginTime: 12/20/2020 7:11:25 PM (1608509485)
Duration: 00:00:03.3462766
MessagesActualLength: 11
WarningsActualLength: 0
ErrorsActualLength: 0
Another question is whether metadata should be per-backup-run in its own file (if so, what happens if the backup that it describes gets removed by retention policy) or a summary of all backups ever or still there.
EDIT:
For a summary without run time, here’s a find command run from GUI Commandline but it could easily be run from a true CLI or a script using Export As Command-line. See how retention policy thins old versions:
Running commandline entry
Finished!
Listing filesets:
0 : 2/8/2022 10:50:50 AM (7716 files, 12.20 GB)
1 : 2/8/2022 9:50:06 AM (7716 files, 12.20 GB)
2 : 2/8/2022 8:50:04 AM (7716 files, 12.20 GB)
3 : 2/8/2022 7:50:04 AM (7716 files, 12.20 GB)
4 : 2/8/2022 7:21:09 AM (7716 files, 12.20 GB)
5 : 2/7/2022 9:50:15 PM (7716 files, 12.20 GB)
6 : 2/7/2022 8:50:05 PM (7716 files, 12.20 GB)
7 : 2/7/2022 7:50:05 PM (7716 files, 12.20 GB)
8 : 2/7/2022 6:50:05 PM (7716 files, 12.20 GB)
9 : 2/7/2022 5:50:04 PM (7716 files, 12.20 GB)
10 : 2/7/2022 4:50:05 PM (7716 files, 12.20 GB)
11 : 2/7/2022 3:50:03 PM (7716 files, 12.20 GB)
12 : 2/7/2022 2:50:04 PM (7716 files, 12.20 GB)
13 : 2/7/2022 1:50:04 PM (7716 files, 12.20 GB)
14 : 2/7/2022 12:50:00 PM (7716 files, 12.20 GB)
15 : 2/7/2022 11:50:04 AM (7716 files, 12.20 GB)
16 : 2/7/2022 8:50:03 AM (7716 files, 12.20 GB)
17 : 2/6/2022 7:59:24 AM (7716 files, 12.20 GB)
18 : 2/5/2022 7:50:02 AM (7716 files, 12.19 GB)
19 : 2/4/2022 7:50:02 AM (7716 files, 12.19 GB)
20 : 2/3/2022 7:50:02 AM (7716 files, 12.19 GB)
21 : 2/2/2022 7:15:37 AM (7716 files, 12.19 GB)
22 : 1/25/2022 6:50:04 PM (7715 files, 12.14 GB)
23 : 1/18/2022 4:50:00 PM (7716 files, 12.36 GB)
24 : 1/11/2022 11:50:17 AM (7715 files, 12.36 GB)
25 : 12/13/2021 9:50:01 AM (6998 files, 12.31 GB)
26 : 11/12/2021 7:43:52 AM (6971 files, 12.29 GB)
27 : 10/6/2021 5:50:03 PM (706 files, 549.28 MB)
Return code: 0
A version number is just UI convenience identifier. Above is current backup state, but not total history.