Avoid InstallationDirectory variable mangled by automounter?

Our installation has managed to hard-code the underlying automounter
path into the configuration, so we see

=$InstallationDirectory /am/servername/real/path/to/topdir/10.3

and

=$Path {"/am/servername/real/path/to/topdir/10.3/AddOns/Applications", \ "/list/of/other/paths ...}

We’re keen to remove the "/am/servername/" prefix from the configuration,
because the nature of our automounter can result in such paths not being
visible until the automouted path has been established.

I believe that Mathematica, in common with a number of other software
systems, all have installtion methodologies that resolve autmounted
paths and store those, rather than the mount points.

If one wishes to force a Mathematica installtion to respect a desired path
as the value of $InstallationDirectory, can that be done, and if so, how?

I’ve taken a detailed look at the startup scripts in case there was an obvious
varibale to override there, or some other way to handle/ferkel automounter
resolution (eg, Matlab’s AUTOMOUNT_MAP varianble) but I can’t see
anything obvious.

Any clues, and apologies for mentioning Matlab,

Kevin Buckley

ECS. VUW, NZ