Just FYI:
I upgraded by Ontap 9.6 SIMULATOR from 9.6 to 9.6P4 using standard Prod ONTAP Image and it worked. Thanks to Alex in the thread I mentioned. I have been using simulators for sometime now, but had never upgraded the SIMULATOR, infact I wasn't aware if it is possible. It does work. You should be alright, good luck!
Upgraded my SImulator From 9.6 to 9.6 P4:
ONTAP96::> cluster image show
Node Current Version Installation Date
-------------------- ----------------------- -------------------
ONTAP96-01 9.6P4 11/26/2019 21:10:58
ONTAP96-02 9.6P4 11/26/2019 22:07:46
2 entries were displayed.
ONTAP96::*> system node image show
Is Is Install
Node Image Default Current Version Date
-------- ------- ------- ------- ------------------------- -------------------
ONTAP96-01
image1 false false 9.6 -
image2 true true 9.6P4 11/26/2019 21:10:58
ONTAP96-02
image1 false false 9.6 -
image2 true true 9.6P4 11/26/2019 22:07:46
4 entries were displayed.