I usually get my answers thru searching, but today I'm struggling to find a solution. Thank you all in advance.
A case (Case# 01982449) was opened and closed some time ago. Support was unable to advise on a script for whatever reason.

For some background we are running Veeam B&R 9.0 v. 9.0.0.1715. Disk backup mode is set to reverse incremental. Backups run in the evenings Monday thru Friday. Backup to Tape jobs start Saturday 7AM. The tape job is configured to run Daily at this time: 7AM, On these days: Saturday.
The problem is we have a backup to tape job that is dependent\linked to a backup job (fileserver VM). We capture the latest full from disk backup on Friday and write to tape on Saturday. The issue is if the disk backup on Friday night runs longer than expected and finishes after the scheduled tape backup starts, the tape job shows successful, however nothing is written to tape. Veeam reports there are no new files to backup per job settings, which is expected as the disk backup is still running. In the backup to tape properties under scheduling we have the "wait for backup jobs: If some linked backup jobs are still running, wait for up to: 240 minutes". The disk backup completed within this time range, however the tape job already ran, thus no tapes were written to. What is the intended behavior of this option?
Support advised a custom script would be needed. Does anyone have a script that would run to check that the disk backup (.vbk) is complete and ready before starting the backup to tape job?