Disable installer of adobe reader taking over default association in enterprise deployment

Hello,

I've read through prior questions and the answer "uninstall adobe reader" is not acceptable.

We deploy reader as a default application to all workstations, imaged or as an update. There are several users that are authorized to use acrobat Pro that we deploy on an individual basis.

We want to be able to update all machines with Adobe Acrobat /without/ effecting the users' default app associations.

What setting in the msi do we need to create a transform to prevent? Is there a CMD line option to disable this functionality?

We already configure the default app for acrobat during imaging new machines and do not need adobe's installers to set the defaults for us.

Thanks.