Hello There,
I am a Software Developer with more than 9 years of experience in .NET and SQL Server related projects.
I do not have a working solution at the moment, but from my past experience, this kind of polling can be scheduled with a timer, checking for the hash value of the files / size of the folder remotely and locally and do a quick comparison. This way we will be doing on-demand FTP connection only.
Again depends on the conditions of the server and target file location, whether old files exist, or get cleared off from the server, whether target location can change etc. need to consider the context and then we can approach this accordingly.
Kind Regards,
Mafaz