I use a Table - Post-Read script to hide a custom button and a custom tab based on a user's Role.

retVal = 0

' Show/Hide STS button if user has XXX role
retVal = oSession.AsObject(oSession.Security).IsMember("XXX")
If retVal > 0 Then
retVal = oScript.SetUIControl("BT_Link_2", "SHOW")
Else
retVal = oScript.SetUIControl("BT_Link_2", "HIDE")
End If

' Show/Hide panel if user has XXX role
retVal = oSession.AsObject(oSession.Security).IsMember("XXX")
If retVal > 0 Then
retVal = oScript.SetUIControl("fldr.PNL_CMNEW_2", "SHOW")
Else
retVal = oScript.SetUIControl("fldr.PNL_CMNEW_2", "HIDE")
End If

You may be able to tweak that based on your UDF.

Sounds great! I'm going to give this a try asap. Thank you!

In later versions (2015 and above?) you can attach a script to a customized screen.

Go to Customizer selection. Select the panel you want to add the script to (right click and select UI_Script Events and then add the event. You have an option of Panel - Post Load and Panel - OnExit.

They are on 2013, but I forgot about this function. I will try that in future. Thanks.