Figured this one out....
Building a distribution package with a Windows Action to launch an executable builds the following script :
Start-Process -wait "exe_path"
if ($? -ne $true)
{
exit 1
}
The wait param coupled with logic to exit (aka continue the provisioning task) if the process fails will functionally hold up ldprovisioning at that step if the program will not close w/o user interaction. I removed the -wait param from Start-Process and was able to get ldprovisioning to exit gracefully.