Improve Frends.SFTP.DownloadFiles "preserve last modified" consistency

We've noticed that Frends.SFTP.DownloadFiles.2.14.0 sometimes fails to keep the last modified -timestamps for downloaded files. For example we had 564 files in source directory, and when they were downloaded and copied to target directory (a folder in SMB fileshare) in a single task execution, last modified timestamps were correctly preserved for most of the files, but still there were 14 files, which had their last modified -timestamp pointing to time of transfer, not preserving the original last modified timestamp in the source. How does the task handle preserving the last modified timestamp part: does it verify that the last update timestamp actually changed on the file level? User should have control on deciding what should happen, if last update timestamp cannot be preserved for some reason, as in certain use cases users might require that the last update timestamps have to be preserved 100% accurately, and if this cannot be done, transfer cannot be treated as succesfully performed, ie. delete the file from destination and keep the source file and throw an error.