are incremental backups to ftp supported if the cbu file is compressed?
Yes they are.
then i must have found a bug cuz i setup an incremental backup to my ftp server for my documents. i saved the backup and tried it to make sure it worked and everytime i launch it it does a backup of everything not what was changed
Ftp backup doesn’t support appending changes to same backup file.
You need use macros in backup step 3 to make sure the name of the backup files are different with each run.