There is a 160F temp bypass on the cooler line. You would need to some how deal with sustained hot oil to make it work and the risks of air being introduced.
Only approved oils will be warrantied. A poor guy found out the hard way when his warrantee was denied. The trans failure with Amsoil was not due to the failure from it but from glycol contamination from the factory.
The oils that are recommended by the companies but not approved will void...