Post-Job Force Full weekly script
Regular chaining of Backup Plans does not allow to schedule a Full of the chained Backup Plan and this is an important option for Image Based Backup Plans. However using a Powershell script to chain plans can help you achieve the desired setup.
In order for this solution to be implemented please make sure your setup meets the requirements from https://kb.cloudberrylab.com/managed-backup-service/powershell-module/get-started
Below is an example of the post job script doing exactly that:
powershell -command "Start-MBSBackupPlan -Name 'Image-Based to Cloud' -ForceFull -ForceFullDayOfWeek 'Friday' "
You can replace "Friday" with another day of the week and replace "Image-Based to Cloud" with name of chained backup plan.
This solution was tested to work only if second plan has no schedule on its own.