Hi,
I'm not sure if I understand Your Problem but let me give it a try.
It cost me some time as well to get "Run as" working as it should.
The "Run as" User configured in SnapCenter (settings->Run As Credentials) is an ordinary System-User at Host side, granted by some root or administrator
privileges -also at the host side.
So as an example, I`m snapping hana databases on linux hosts and so I need a user on the hana-host side who is able to do a ssh login and need some additional
sodo privileges.
My Unix-Admin added a function-user named "fcsnap" on the HANA_HOST1.
fcsnap is allowed login to the hana host by ssh and password (not passphrase) and to do some sodo-commands, declared inside the /etc/sodoers.d/fcsnap configuration file:
###############
cmnd_Alias NETAPP_SCCMD = /tmp/sc-plugin-installer/snapcenter_linux_host_plugin.bin *, \
/opt/NetApp/snapcenter/spl/installation/plugins/uninstall, \
/opt/NetApp/snapcenter/spl/bin/spl
Cmnd_Alias NETAPP_PRECHECKCMD = /tmp/netapp/Linux_Prechecks.sh
fcsnap ALL=(ALL) NOPASSWD:SETENV: NETAPP_SCCMD, NETAPP_PRECHECKCMD
Defaults:fcsnap !visiblepw
Defaults:fcsnap !requiretty
###############
so at snapcenter runas config, the "run as name" is "HANA_HOST1_fcsnap"
where the "username" is "fcsnap",
the password is the "password" given by my uni-admin
and "Authentication" is "Linux"
If You have a Windows host, it should be very semiar (I have no experience in Windows User privilege management)
Let me know if this helps You a bit or if I totaly misunderstood Your Problem.