Yes, there is no problem deleting these DMP files from Windows Explorer or CMD.EXE.
However, it's best to check with the retention from the created policy, which ones are still supposed to exist, and leave those on the drive.
When scheduling the repository backup from Powershell, the scheduling and retention is given, and the backup is implemented as a special task in Windows Task Scheduler, with its own resource group and its own policy.
The resource group is named
"MYSQL_DS_SC_Repository", and the policy is named
Powershell can be used to request the policy information on this policy or all policies on this resource group:
PS C:\Users\<USER>> Open-SmConnection
PS C:\Users\<USER>> Get-SmPolicy -PolicyName "MYSQL_Backup_SC_Repository"
PS C:\Users\<USER>> Get-SmPolicy -DatasetName "MYSQL_DS_SC_Repository"