I was evaluating the Metalogix tool for Migration from fileshare to SharePoint. The file share edition needs to be selected while installing the Metalogix content matrix tool. The good news is that it can fulfil the following requirements:
Migrate files recursively from within folders , i.e. flatten folder Replace illegal characters with character specified Handle duplicate by either overwriting file or not moving file The CreatedBy, CreatedDate, ModifedBy and ModifiedDate file properties can be maintained by mapping these properties to SharePoint respective Out of the Box columns Can apply custom filter on the following Created Before Created After Modified Before Modified After File Size Max Can migrate user permission as set on the folder/file from fileShare to SharePoint, however I could not find option how to map to SharePoint Groups.