Hello mdpowers,

look in your projectfolder for the .csproj file.
Open the file with wordpad and look for the section:

 <PropertyGroup>
   <!--
       properites needed to register addins
       AddinRegistryHive - Root registry hive for the addin
       AddinRegistryKey  - Registry key where this addin is registered
   -->
   <AddinRegistryHive>CurrentUser</AddinRegistryHive>
   
<AddinRegistryKey>Software\Microsoft\Office\Outlook\Addins</AddinRegistryKey>
 </PropertyGroup>

change CurrentUser to LocalMachine
Maybe that helps.