I have condition, where I need to switch form to read only view, if field status equals "Approved" or "Rejected".
I've created intermediate variable called "CurrentStatus", which is taking 1 if status is "Approved" or "Rejected", else it's taking 0 (this rule on Status field).
Then on Form Load I've put condition:
If CurrentStatus Is Equal to 1
Switch form to Read Only View
It works well if you will create new form, but It won't work for existing forms, even if you resubmit the form with new status.