PowerShell adjust secruity on session items

Hello there,

i'm currently working on a powershell script to automize most of the tasks for new users / groups in RDM.

i'm now facing a issue where i want to assign a specific toplogy of roles and users to a new VAULT.

Like this:
Role A, B, C and so on
New Vault (No Secruity Setttings / No one can add or edit something)
- Folder 1
--Session Secruity Custom: Role A Full Control
- Folder 2
--Session Secruity Custom: Role B Full Control
- Folder 3
--Session Secruity Custom: Role C Full Control
...

Everything is fine until i want to edit the Secruity permissions on the folders/session.
$rdmvault="New Vault"
$rdmrole="Role A"
$rdmfolder="Folder A"
#help https://forum.devolutions.net/topics/29552/powershell-script-to-remove-security-groups-and-set-view-permission-on
#https://forum.devolutions.net/topics/29716/renaming-a-role-and-update-permissionsg
$role=Get-RDMRole -Name $rdmrole
$vault=Get-RDMVault -Name $rdmvault

Set-RDMCurrentRepository $vault
Update-RDMUI
New-RDMSession -Name $rdmfolder -Type Group -SetSession

$sess=Get-RDMSession -Name $rdmfolder
# Set the View Permission
$view = @()
$view += $rdmrole
$sess.Security.ViewOverride = "Custom"
$sess.Security.ViewRoles = $view
$sess.Security.RoleOverride = "Custom"

Set-RDMSession $sess -Refresh
Update-RDMUI

So with the above settings i am able to edit the view permissions as mentioned in a other forum article.
To my bad i cannot add others.

I could create a template where i place some settings and edit it, but thats not the result i want to have. I want to compleatly add new permissions.
With that i am able to view the current settings as mentioned before.
$sess.Security.Permissions


IsEmpty : False
Override : Custom
Right : Add
Roles : {Role_A}
RoleValues : Role_A

How can i add new secruity settings like, "EDIT", "DELETE" and so on?

Many thanks