Silent service pack install for Client Access for Windows

Our environment: v7r1 i/OS, Windows 7 Enterprise, i Access for Windows v7r1
(currently at SI53809), no one has admin privileges on their Windows client
(so, installing software requires admin privileges). I did RTFM including
a redbook "iSeries Access for Windows V5R2 Hot Topics" from 13 years ago,
and Google was not my friend.

We want to *silently* apply the latest service pack (SI56695) to 200+
clients. Apparently, our infrastructure peeps can't manage to deploy this
(I don't know the details, as a lot of things around here are on a
need-to-know basis, as in "you don't need to know the details, but I know
this won't work"). For this reason, replacing the WIndows client with the
Java client (iACS) is out of the question.

I have a vague idea that an "Administration System" assigned in the i
Access for Windows Properties tab by the same name can be used as the
source for a service pack install, and then the Service tab allows the
setting of options including silent installation. (I have access only to
our dev box, but I was unable to assign it to be our administration system,
with error "The specified system is not an administration system.") Does
anyone have experience with how "silent" this actually is? Our users power
down their Windows client every night so, ideally, the service pack would
download on day 1 and install when the client is powered up on day 2. The
users normally start their Client Access session almost as soon as Windows
allows them to.

The big problem as I see it is, if all of our Client Access installations
are like mine, neither the Administration System is defined nor is the
silent installation option selected in the i Access for Windows
Properties. Unless I'm unaware of some magic button that the i server has
available to set those on the clients, I'm probably in the same hole as
having the infrastructure peeps being unable to deploy the service pack.
Yay/nay?

- Dan