Hi
it's not exists. it used to work on 7-mode thanks to the RPC services and computer account the filer had, in Cdot the computer account is of the SVM and RPC only availble on the SVM itself. not on the cluster/node so they cannot authenticate in the same way.
See BURT
https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=826138
if you store the cred using PS secure cred to a XML/json/txt. only the user who encrypted the cred can read it, so if you using the same user that you let's say run a sched task with (if you trust that it is safe), you are not really exposing "new" risk by leaving this file behind (as whoever manages to exploit it - need anyway to have access to the user)